Não informado. (1972). Alternative sources of energy. Alternative Sources of Energy.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Alternative Sources of Energy. Milaca, Minn: Alternative Sources of Energy, 1972.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Alternative Sources of Energy. Alternative Sources of Energy, 1972.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.