Gaya APA

Virts, W, B., Institute, A, H, &, M, A, E. (1987). Purchasing for hospitality operations . Michigan: Educational Institute of AHMA.

Gaya MLA

Virts, William, B.., Institute, American, Hotel, &, Motel, Association., Educational. "Purchasing for hospitality operations". Michigan: Educational Institute of AHMA, 1987. BUKU.