diff --git a/src/main/java/com/epam/izh/rd/online/Main.java b/src/main/java/com/epam/izh/rd/online/Main.java
index e3939a4b..00109f5a 100644
--- a/src/main/java/com/epam/izh/rd/online/Main.java
+++ b/src/main/java/com/epam/izh/rd/online/Main.java
@@ -3,7 +3,6 @@
 public class Main {
 
     public static void main(String[] args) {
-
     }
 
 }
diff --git a/src/main/java/com/epam/izh/rd/online/entity/Author.java b/src/main/java/com/epam/izh/rd/online/entity/Author.java
index 166be587..3a00906b 100644
--- a/src/main/java/com/epam/izh/rd/online/entity/Author.java
+++ b/src/main/java/com/epam/izh/rd/online/entity/Author.java
@@ -20,4 +20,76 @@
  */
 public class Author {
 
+    private String name;
+    private String lastName;
+    private LocalDate birthdate;
+    private String country;
+
+    public Author() {
+    }
+
+    public Author(String name, String lastName, LocalDate birthdate, String country) {
+        this.name = name;
+        this.lastName = lastName;
+        this.birthdate = birthdate;
+        this.country = country;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public LocalDate getBirthdate() {
+        return birthdate;
+    }
+
+    public void setBirthdate(LocalDate birthdate) {
+        this.birthdate = birthdate;
+    }
+
+    public String getCountry() {
+        return country;
+    }
+
+    public void setCountry(String country) {
+        this.country = country;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Author author = (Author) o;
+        return Objects.equals(name, author.name) &&
+                Objects.equals(lastName, author.lastName) &&
+                Objects.equals(birthdate, author.birthdate) &&
+                Objects.equals(country, author.country);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, lastName, birthdate, country);
+    }
+
+    @Override
+    public String toString() {
+        return "Author{" +
+                "name='" + name + '\'' +
+                ", lastName='" + lastName + '\'' +
+                ", birthdate=" + birthdate +
+                ", country='" + country + '\'' +
+                '}';
+    }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/entity/Book.java b/src/main/java/com/epam/izh/rd/online/entity/Book.java
index 08bdccb8..8f079869 100644
--- a/src/main/java/com/epam/izh/rd/online/entity/Book.java
+++ b/src/main/java/com/epam/izh/rd/online/entity/Book.java
@@ -17,4 +17,52 @@
  */
 public abstract class Book {
 
+    private int numberOfPages;
+    private String name;
+
+    public Book() {
+    }
+
+    public Book(int numberOfPages, String name) {
+        this.numberOfPages = numberOfPages;
+        this.name = name;
+    }
+
+    public int getNumberOfPages() {
+        return numberOfPages;
+    }
+
+    public void setNumberOfPages(int numberOfPages) {
+        this.numberOfPages = numberOfPages;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Book book = (Book) o;
+        return numberOfPages == book.numberOfPages &&
+                Objects.equals(name, book.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(numberOfPages, name);
+    }
+
+    @Override
+    public String toString() {
+        return "Book{" +
+                "numberOfPages=" + numberOfPages +
+                ", name='" + name + '\'' +
+                '}';
+    }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java b/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java
index a9834db4..fb67fb6e 100644
--- a/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java
+++ b/src/main/java/com/epam/izh/rd/online/entity/SchoolBook.java
@@ -21,4 +21,66 @@
  */
 public class SchoolBook extends Book {
 
+    private String authorName;
+    private String authorLastName;
+    private LocalDate publishDate;
+
+    public SchoolBook() {
+    }
+
+    public SchoolBook(int numberOfPages, String name, String authorName, String authorLastName, LocalDate publishDate) {
+        super(numberOfPages, name);
+        this.authorName = authorName;
+        this.authorLastName = authorLastName;
+        this.publishDate = publishDate;
+    }
+
+    public String getAuthorName() {
+        return authorName;
+    }
+
+    public void setAuthorName(String authorName) {
+        this.authorName = authorName;
+    }
+
+    public String getAuthorLastName() {
+        return authorLastName;
+    }
+
+    public void setAuthorLastName(String authorLastName) {
+        this.authorLastName = authorLastName;
+    }
+
+    public LocalDate getPublishDate() {
+        return publishDate;
+    }
+
+    public void setPublishDate(LocalDate publishDate) {
+        this.publishDate = publishDate;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if (!super.equals(o)) return false;
+        SchoolBook that = (SchoolBook) o;
+        return Objects.equals(authorName, that.authorName) &&
+                Objects.equals(authorLastName, that.authorLastName) &&
+                Objects.equals(publishDate, that.publishDate);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), authorName, authorLastName, publishDate);
+    }
+
+    @Override
+    public String toString() {
+        return "SchoolBook{" +
+                "authorName='" + authorName + '\'' +
+                ", authorLastName='" + authorLastName + '\'' +
+                ", publishDate=" + publishDate +
+                '}';
+    }
 }
diff --git a/src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java b/src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java
new file mode 100644
index 00000000..0a4bef3c
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/repository/SimpleAuthorRepository.java
@@ -0,0 +1,39 @@
+package com.epam.izh.rd.online.repository;
+
+import com.epam.izh.rd.online.entity.Author;
+
+import java.util.Arrays;
+import java.util.stream.Stream;
+
+public class SimpleAuthorRepository implements AuthorRepository{
+
+    private Author[] authors = new Author[] {};
+
+    @Override
+    public boolean save(Author author) {
+        if (findByFullName(author.getName(), author.getLastName()) != null) return false;
+        authors = Stream.concat(Arrays.stream(authors), Stream.of(author)).toArray(Author[]::new);
+        return true;
+    }
+
+    @Override
+    public Author findByFullName(String name, String lastName) {
+        for (Author author : authors) {
+            if (author.getName().toUpperCase().equals(name.toUpperCase()) &&
+                    author.getLastName().toUpperCase().equals(lastName.toUpperCase())) return author;
+        }
+        return null;
+    }
+
+    @Override
+    public boolean remove(Author author) {
+        int countBefore = count();
+        authors = Arrays.stream(authors).filter(o -> !o.equals(author)).toArray(Author[]::new);
+        return countBefore != count();
+    }
+
+    @Override
+    public int count() {
+        return authors.length;
+    }
+}
diff --git a/src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java b/src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java
new file mode 100644
index 00000000..e676c8c9
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/repository/SimpleSchoolBookRepository.java
@@ -0,0 +1,34 @@
+package com.epam.izh.rd.online.repository;
+
+import com.epam.izh.rd.online.entity.SchoolBook;
+
+import java.util.Arrays;
+import java.util.stream.Stream;
+
+public class SimpleSchoolBookRepository implements BookRepository<SchoolBook>{
+
+    private SchoolBook[] schoolBooks = new SchoolBook[] {};
+
+    @Override
+    public boolean save(SchoolBook book) {
+        schoolBooks = Stream.concat(Arrays.stream(schoolBooks), Stream.of(book)).toArray(SchoolBook[]::new);
+        return true;
+    }
+
+    @Override
+    public SchoolBook[] findByName(String name) {
+        return Arrays.stream(schoolBooks).filter(book -> book.getName().equals(name)).toArray(SchoolBook[]::new);
+    }
+
+    @Override
+    public boolean removeByName(String name) {
+        int countBefore = count();
+        schoolBooks = Arrays.stream(schoolBooks).filter(book -> !book.getName().equals(name)).toArray(SchoolBook[]::new);
+        return countBefore != count();
+    }
+
+    @Override
+    public int count() {
+        return schoolBooks.length;
+    }
+}
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java
new file mode 100644
index 00000000..35d81cb9
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleAuthorService.java
@@ -0,0 +1,36 @@
+package com.epam.izh.rd.online.service;
+
+import com.epam.izh.rd.online.entity.Author;
+import com.epam.izh.rd.online.repository.AuthorRepository;
+
+public class SimpleAuthorService implements AuthorService{
+
+    private AuthorRepository authorRepository;
+
+    public SimpleAuthorService() {
+    }
+
+    public SimpleAuthorService(AuthorRepository authorRepository) {
+        this.authorRepository = authorRepository;
+    }
+
+    @Override
+    public boolean save(Author author) {
+        return authorRepository.save(author);
+    }
+
+    @Override
+    public Author findByFullName(String name, String lastName) {
+        return authorRepository.findByFullName(name, lastName);
+    }
+
+    @Override
+    public boolean remove(Author author) {
+        return authorRepository.remove(author);
+    }
+
+    @Override
+    public int count() {
+        return authorRepository.count();
+    }
+}
diff --git a/src/main/java/com/epam/izh/rd/online/service/SimpleSchoolBookService.java b/src/main/java/com/epam/izh/rd/online/service/SimpleSchoolBookService.java
new file mode 100644
index 00000000..f04f79e0
--- /dev/null
+++ b/src/main/java/com/epam/izh/rd/online/service/SimpleSchoolBookService.java
@@ -0,0 +1,55 @@
+package com.epam.izh.rd.online.service;
+
+import com.epam.izh.rd.online.entity.Author;
+import com.epam.izh.rd.online.entity.SchoolBook;
+import com.epam.izh.rd.online.repository.BookRepository;
+
+public class SimpleSchoolBookService implements BookService<SchoolBook>{
+
+    private BookRepository<SchoolBook> schoolBookBookRepository;
+    private AuthorService authorService;
+
+    public SimpleSchoolBookService() {
+    }
+
+    public SimpleSchoolBookService(BookRepository<SchoolBook> schoolBookBookRepository, AuthorService authorService) {
+        this.schoolBookBookRepository = schoolBookBookRepository;
+        this.authorService = authorService;
+    }
+
+    @Override
+    public boolean save(SchoolBook book) {
+        if (authorService.findByFullName(book.getAuthorName(), book.getAuthorLastName()) != null) {
+            schoolBookBookRepository.save(book);
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public SchoolBook[] findByName(String name) {
+        return schoolBookBookRepository.findByName(name);
+    }
+
+    @Override
+    public int getNumberOfBooksByName(String name) {
+        return schoolBookBookRepository.findByName(name).length;
+    }
+
+    @Override
+    public boolean removeByName(String name) {
+        return schoolBookBookRepository.removeByName(name);
+    }
+
+    @Override
+    public int count() {
+        return schoolBookBookRepository.count();
+    }
+
+    @Override
+    public Author findAuthorByBookName(String name) {
+        SchoolBook[] schoolBooks = schoolBookBookRepository.findByName(name);
+        if (schoolBooks == null || schoolBooks.length == 0) return null;
+        return authorService.findByFullName(schoolBooks[0].getAuthorName(), schoolBooks[0].getAuthorLastName());
+    }
+}