Gaya APA

Colton, D., Covert, R, W. (2007). Designing and constructing instruments for social research and evaluation . San Francisco: John Wiley & Sons, Inc.

Gaya MLA

Colton, David., Covert, Robert, W.. "Designing and constructing instruments for social research and evaluation". San Francisco: John Wiley & Sons, Inc, 2007. MM.