bugfix: Literature needed to be registered in admin.py

input/admin.py

@@ -4,7 +4,7 @@ from django.contrib import admin
 from django.http import HttpResponse
 
 from .models import Project, HonoraryCertificate, Library, IFG, Travel,\
-                    Email, BusinessCard, List
+                    Email, BusinessCard, List, Literature
 
 
 def export_as_csv(self, request, queryset):
@@ -41,5 +41,6 @@ admin.site.register([
                      Travel,
                      Email,
                      BusinessCard,
-                     List
+                     List,
+                     Literature,
                      ])