O'Brien, R. (1980). Machines (2nd ed.). Time-Life Books.
Chicago Style (17th ed.) CitationO'Brien, Robert. Machines. 2nd ed. Hong Kong: Time-Life Books, 1980.
MLA (9th ed.) CitationO'Brien, Robert. Machines. 2nd ed. Time-Life Books, 1980.
Warning: These citations may not always be 100% accurate.