The evolution of the flying machine ; balloon: airship: airplane
MLA
Harper, Harry. The Evolution of the Flying Machine: Balloon: Airship: Airplane. Philadelphia: McKay, 1930
APA, 7th edition
Harper, H. (1930). The evolution of the flying machine: balloon: airship: airplane. Philadelphia: McKay
Chicago, 17th edition
Harper, Harry. The evolution of the flying machine: balloon: airship: airplane. Philadelphia: McKay, 1930