+ rel_info = book.related_info()
+ names = [(name, Tag.create_url('author', slug))
+ for name, slug in rel_info['tags']['author']]
+ if 'parents' in rel_info:
+ books = [(name, Book.create_url(slug))
+ for name, slug in rel_info['parents']]
+ names.extend(reversed(books))
+ names.append((self.title, self.get_absolute_url()))