diff --git a/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java b/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java
index b6452cb..7d7b6d0 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/PublicBookManager.java
@@ -5,6 +5,7 @@
 import org.springframework.stereotype.Repository;
 
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.regex.*;
@@ -13,13 +14,10 @@
 @Repository
 public class PublicBookManager implements IBookListener{
 
-    private final BookManager bookManager;
-
     private final HashMap<String, HashSet<Book>> publicBooks = new HashMap<>();
 
     public PublicBookManager(BookManager bookManager) {
-        this.bookManager = bookManager;
-        this.bookManager.addListener(this);
+        bookManager.addListener(this);
     }
 
     public ArrayList<Book> getAllPublicBooks(){
@@ -43,7 +41,13 @@
         return books;
     }
 
+
     public ArrayList<Book> searchBooksByTitle(String title, int sortBy){
+        if(sortBy == 0){
+            ArrayList<Book> result = searchBooksByTitle(title);
+            result.sort(Comparator.comparing(Book::getTime).reversed());
+            return result;
+        }
         return null;
     }
 
@@ -60,17 +64,23 @@
     }
 
     public ArrayList<Book> searchBooksByAccount(String accountId, int sortBy){
+        if(sortBy == 0){
+            ArrayList<Book> result = searchBooksByAccount(accountId);
+            result.sort(Comparator.comparing(Book::getTime).reversed());
+            return result;
+        }
         return null;
     }
 
     public ArrayList<Book> searchBooksByTitleAndAccount(String title, String accountId){
         ArrayList<Book> books = searchBooksByTitle(title);
+        ArrayList<Book> result = new ArrayList<>();
         for(Book book : books){
             if(book.getAccountId().equals(accountId)){
-                books.add(book);
+                result.add(book);
             }
         }
-        return books;
+        return result;
     }
 
     @Override