Gaya APA

Schorr, J, E. (1992). Purchasing In The 21st Century : A Guide To State-Of-The-Art Techniques And Strategies . United States of America: Oliver Wight Publications, Inc.

Gaya MLA

Schorr, John, E.. "Purchasing In The 21st Century : A Guide To State-Of-The-Art Techniques And Strategies". United States of America: Oliver Wight Publications, Inc, 1992. Text.