Gaya APA

Niebel, A, F, B, W. (2009). Niebel's methods, standards, and work design (Twelfth edition). : McGraw-Hill Higher Education.

Gaya MLA

Niebel, Andris, Freivalds,, Benjamin, W.. "Niebel's methods, standards, and work design". Twelfth edition : McGraw-Hill Higher Education, 2009. Text.