Gaya APA

England, M, R, L, ;, H, E, F, ;, W, B. (1989). Purchasing and materials management (ed. 9). Boston: Irwin.

Gaya MLA

England, Michiel, R., Leenders, ;, Harold, E., Fearon, ;, Wilbur, B.. "Purchasing and materials management". ed. 9 Boston: Irwin, 1989. Text.