+ def authors_first_names(self):
+ return ', '.join(a.first_name for a in self.authors.all())
+
+ def authors_last_names(self):
+ return ', '.join(a.last_name for a in self.authors.all())
+
+ def translators_first_names(self):
+ return ', '.join(a.first_name for a in self.translators.all())
+
+ def translators_last_names(self):
+ return ', '.join(a.last_name for a in self.translators.all())
+