Kurth, H. (1975). Helicopters. World's Work.
Chicago Style (17th ed.) CitationKurth, Heinz. Helicopters. Kingswood, Tadworth, Surrey: World's Work, 1975.
MLA (9th ed.) CitationKurth, Heinz. Helicopters. World's Work, 1975.
Warning: These citations may not always be 100% accurate.