Não informado. (1972). Alternative sources of energy. Alternative Sources of Energy.
Chicago-Zitierstil (17. Ausg.)Não informado. Alternative Sources of Energy. Milaca, Minn: Alternative Sources of Energy, 1972.
MLA-Zitierstil (8. Ausg.)Não informado. Alternative Sources of Energy. Alternative Sources of Energy, 1972.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.