Gaya APA

FREIVALDS, A., NIEBEL, B, W. (2009). Niebel's methods, standards, and work design, twelfth edition (Twelfth). Singapura: McGraw Hill.

Gaya MLA

FREIVALDS, Andris., NIEBEL, Benjamin, W.. "Niebel's methods, standards, and work design, twelfth edition". Twelfth Singapura: McGraw Hill, 2009. Text.