Fraenkel, J. R., & Wallen, N. E. (2009). How to design and evaluate research in education (7th ed.). McGraw-Hill.
Cita Chicago (17th ed.)Fraenkel, Jack R., i Norman E. Wallen. How to Design and Evaluate Research in Education. 7th ed. Boston: McGraw-Hill, 2009.
Cita MLA (9th ed.)Fraenkel, Jack R., i Norman E. Wallen. How to Design and Evaluate Research in Education. 7th ed. McGraw-Hill, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.