Gaya APA

Crom, D, C, A, A, I, J, O, C, D, M. (2011). The SALES Advantage . 27 april 2011: Erlangga.

Gaya MLA

Crom, Dale, Carnegie, And, Associates,, Inc.,, J., Oliver, Crom,, Dan, Michael. "The SALES Advantage". 27 april 2011: Erlangga, 2011. Text.