Gaya APA

Virts, W, B. (1987). Purchasing For Hospitality Operations (Cetakan I). United States Of America: The Educational Institute Of The American Hotel & Motel Association.

Gaya MLA

Virts, William, B.. "Purchasing For Hospitality Operations". Cetakan I United States Of America: The Educational Institute Of The American Hotel & Motel Association, 1987. .