Fraenkel, J. R., & Wallen, N. E. (2019). How to design and evaluate research in education. McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Fraenkel, Jack R., agus Norman E. Wallen. How to Design and Evaluate Research in Education. Boston: McGraw-Hill, 2019.
Lua MLA (9ú heag.)Fraenkel, Jack R., agus Norman E. Wallen. How to Design and Evaluate Research in Education. McGraw-Hill, 2019.