Gaya APA

Fraenkel, J, R., Wallen, N, E. (2007). How to Design and Evaluate Research in Education (6). Amerika: McGraw-Hill Publishing Company.

Gaya MLA

Fraenkel, Jack, R.., Wallen, Norman, E.. "How to Design and Evaluate Research in Education". 6 Amerika: McGraw-Hill Publishing Company, 2007. Text.