Não informado. (1981). Energy progress. American Institute of Chemical Engineers.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Energy Progress. New York: American Institute of Chemical Engineers, 1981.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Energy Progress. American Institute of Chemical Engineers, 1981.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.