diff --git a/CalibreWebCompanion/db.sqlite3 b/CalibreWebCompanion/db.sqlite3
index d5c379a..67f7a65 100644
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diff --git a/CalibreWebCompanion/library/__pycache__/forms.cpython-38.pyc b/CalibreWebCompanion/library/__pycache__/forms.cpython-38.pyc
index a27ce3b..81af47a 100644
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diff --git a/CalibreWebCompanion/library/__pycache__/models.cpython-38.pyc b/CalibreWebCompanion/library/__pycache__/models.cpython-38.pyc
index 9625490..8b6e950 100644
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diff --git a/CalibreWebCompanion/library/__pycache__/views.cpython-38.pyc b/CalibreWebCompanion/library/__pycache__/views.cpython-38.pyc
index f897e15..d6d40ff 100644
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diff --git a/CalibreWebCompanion/library/forms.py b/CalibreWebCompanion/library/forms.py
index 319166a..7a28e4c 100644
--- a/CalibreWebCompanion/library/forms.py
+++ b/CalibreWebCompanion/library/forms.py
@@ -6,7 +6,7 @@ from django.contrib.auth.models import User
 class SearchForm(forms.Form):
     title = forms.CharField(label="Title", max_length=200)
     author = forms.CharField(label='Author', max_length=100)
-    # identifier = forms.CharField(label='Identifier(ISBN, Google-id, amazon id)', max_length=20)
+    identifier = forms.CharField(label='Identifier(ISBN, Google-id, amazon id)', max_length=20)
 
 
 
diff --git a/CalibreWebCompanion/library/models.py b/CalibreWebCompanion/library/models.py
index 0635566..0943333 100644
--- a/CalibreWebCompanion/library/models.py
+++ b/CalibreWebCompanion/library/models.py
@@ -57,7 +57,7 @@ class Data(models.Model):
 
 
 class Identifier(models.Model):
-    book = models.IntegerField()
+    book = models.ForeignKey("Book", db_column="book", on_delete=models.CASCADE)
     type = models.TextField()
     val = models.TextField()
 
diff --git a/CalibreWebCompanion/library/templates/search.html b/CalibreWebCompanion/library/templates/search.html
index ba0aad0..7fa03f0 100644
--- a/CalibreWebCompanion/library/templates/search.html
+++ b/CalibreWebCompanion/library/templates/search.html
@@ -8,6 +8,8 @@
     <input id="title" type="text" name="title" value="">
     <label for="author">Author: </label>
     <input id="author" type="text" name="author" value="">
+    <label for="author">Identifier: </label>
+    <input id="identifier" type="text" name="identifier" value="">
     <button class="waves-effect waves-light btn green accent-4" type="submit">search</button>
 </form>
 </div>
diff --git a/CalibreWebCompanion/library/views.py b/CalibreWebCompanion/library/views.py
index bcfaa30..23a0c49 100644
--- a/CalibreWebCompanion/library/views.py
+++ b/CalibreWebCompanion/library/views.py
@@ -1,6 +1,6 @@
 from django.shortcuts import render
 from django.views import generic
-from .models import Author, Book, Comment, Rating, BookAuthorLink, Publisher, Tag, BookTagLink, BookRatingLink, Data
+from .models import Author, Book, Comment, Rating, BookAuthorLink, Publisher, Tag, BookTagLink, BookRatingLink, Data, Identifier
 from django.http import HttpResponseRedirect
 from .forms import SearchForm, UserCreationForm
 from django.db import models
@@ -40,11 +40,14 @@ class ResultsView(generic.ListView):  # no clue if this is secure.
     def get_queryset(self):  # new
         title = self.request.GET.get('title')
         author = self.request.GET.get('author')
+        identifier = self.request.GET.get("identifier")
         books = Book.objects.prefetch_related("tags", "ratings")
         if title:
             books =books.filter(sort__icontains=title)
         if author:
             books = books.filter(author_sort__icontains=author)
+        if identifier:
+            books = books.filter(identifier__val=identifier)
         return books