diff --git a/cps/db.py b/cps/db.py
index aaedcd06..0ae0c858 100644
--- a/cps/db.py
+++ b/cps/db.py
@@ -111,66 +111,70 @@ class Identifiers(Base):
     def format_type(self):
         format_type = self.type.lower()
         if format_type == 'amazon':
-            return u"Amazon"
+            return "Amazon"
         elif format_type.startswith("amazon_"):
-            return u"Amazon.{0}".format(format_type[7:])
+            return "Amazon.{0}".format(format_type[7:])
         elif format_type == "isbn":
-            return u"ISBN"
+            return "ISBN"
         elif format_type == "doi":
-            return u"DOI"
+            return "DOI"
         elif format_type == "douban":
-            return u"Douban"
+            return "Douban"
         elif format_type == "goodreads":
-            return u"Goodreads"
+            return "Goodreads"
         elif format_type == "babelio":
-            return u"Babelio"
+            return "Babelio"
         elif format_type == "google":
-            return u"Google Books"
+            return "Google Books"
         elif format_type == "kobo":
-            return u"Kobo"
+            return "Kobo"
         elif format_type == "litres":
-            return u"ЛитРес"
+            return "ЛитРес"
         elif format_type == "issn":
-            return u"ISSN"
+            return "ISSN"
         elif format_type == "isfdb":
-            return u"ISFDB"
+            return "ISFDB"
         if format_type == "lubimyczytac":
-            return u"Lubimyczytac"
+            return "Lubimyczytac"
+        if format_type == "databazeknih":
+            return "Databáze knih"
         else:
             return self.type
 
     def __repr__(self):
         format_type = self.type.lower()
         if format_type == "amazon" or format_type == "asin":
-            return u"https://amazon.com/dp/{0}".format(self.val)
+            return "https://amazon.com/dp/{0}".format(self.val)
         elif format_type.startswith('amazon_'):
-            return u"https://amazon.{0}/dp/{1}".format(format_type[7:], self.val)
+            return "https://amazon.{0}/dp/{1}".format(format_type[7:], self.val)
         elif format_type == "isbn":
-            return u"https://www.worldcat.org/isbn/{0}".format(self.val)
+            return "https://www.worldcat.org/isbn/{0}".format(self.val)
         elif format_type == "doi":
-            return u"https://dx.doi.org/{0}".format(self.val)
+            return "https://dx.doi.org/{0}".format(self.val)
         elif format_type == "goodreads":
-            return u"https://www.goodreads.com/book/show/{0}".format(self.val)
+            return "https://www.goodreads.com/book/show/{0}".format(self.val)
         elif format_type == "babelio":
-            return u"https://www.babelio.com/livres/titre/{0}".format(self.val)
+            return "https://www.babelio.com/livres/titre/{0}".format(self.val)
         elif format_type == "douban":
-            return u"https://book.douban.com/subject/{0}".format(self.val)
+            return "https://book.douban.com/subject/{0}".format(self.val)
         elif format_type == "google":
-            return u"https://books.google.com/books?id={0}".format(self.val)
+            return "https://books.google.com/books?id={0}".format(self.val)
         elif format_type == "kobo":
-            return u"https://www.kobo.com/ebook/{0}".format(self.val)
+            return "https://www.kobo.com/ebook/{0}".format(self.val)
         elif format_type == "lubimyczytac":
-            return u"https://lubimyczytac.pl/ksiazka/{0}/ksiazka".format(self.val)
+            return "https://lubimyczytac.pl/ksiazka/{0}/ksiazka".format(self.val)
         elif format_type == "litres":
-            return u"https://www.litres.ru/{0}".format(self.val)
+            return "https://www.litres.ru/{0}".format(self.val)
         elif format_type == "issn":
-            return u"https://portal.issn.org/resource/ISSN/{0}".format(self.val)
+            return "https://portal.issn.org/resource/ISSN/{0}".format(self.val)
         elif format_type == "isfdb":
-            return u"http://www.isfdb.org/cgi-bin/pl.cgi?{0}".format(self.val)
+            return "http://www.isfdb.org/cgi-bin/pl.cgi?{0}".format(self.val)
+        elif format_type == "databazeknih":
+            return "https://www.databazeknih.cz/knihy/{0}".format(self.val)
         elif self.val.lower().startswith("javascript:"):
             return quote(self.val)
         else:
-            return u"{0}".format(self.val)
+            return "{0}".format(self.val)
 
 
 class Comments(Base):