(1993). EC study guide to environment-related courses. Luxembourg: Office for Official Publications of the European Communities.
Παραπομπή Chicago StyleEC Study Guide to Environment-related Courses. Luxembourg: Office for Official Publications of the European Communities, 1993.
Παραπομπή MLAEC Study Guide to Environment-related Courses. Luxembourg: Office for Official Publications of the European Communities, 1993.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.