diff --git a/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java b/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java
index 8837331..c65fa4f 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java
@@ -6,6 +6,7 @@
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.regex.*;
 
 public class PublicBookManager implements IBookListener{
 
@@ -24,8 +25,9 @@
 
     public ArrayList<Book> searchBooksByTitle(String title){
         ArrayList<Book> books = new ArrayList<>();
+        var ptn = Pattern.compile(title);
         for(Book book : this.publicBooks){
-            if(book.getTitle().equals(title)){
+            if(ptn.matcher(book.getTitle()).find()){
                 books.add(book);
             }
         }
@@ -37,8 +39,13 @@
     }
 
     public ArrayList<Book> searchBooksByAccount(String accountId){
-
-        return null;
+        ArrayList<Book> books = new ArrayList<>();
+        for(Book book : this.publicBooks){
+            if(book.getAccountId().equals(accountId)){
+                books.add(book);
+            }
+        }
+        return books;
     }
 
     public ArrayList<Book> searchBooksByAccount(String accountId, int sortBy){
@@ -46,11 +53,21 @@
     }
 
     public ArrayList<Book> searchBooksByTitleAndAccount(String title, String accountId){
-        return null;
+        ArrayList<Book> books = searchBooksByTitle(title);
+        for(Book book : books){
+            if(book.getAccountId().equals(accountId)){
+                books.add(book);
+            }
+        }
+        return books;
     }
 
     @Override
     public void bookChanged(Account account, Book book) {
-
+        if(book.getPublicity()){
+            this.publicBooks.add(book);
+        } else{
+            this.publicBooks.remove(book);
+        }
     }
 }