Marczyk, Geoffrey
Essentials of research design and methodology
John Wiley & Sons, 2005
 Buku Teks
Understanding social research: perspectives on methodology and practice
edited by George Mckenzie, Jackie Powell, Robin Usher
The Falmer Press, 1997
 Buku Teks
Creswell, John W.
Research design : qualitative, quantitative, and mixed methods approaches
Sage Publication, Inc, 2003
 Buku Teks
Creswell, John W.
Research design : qualitative, quantitative, and mixed methods approaches
Sage, 2018
 Buku Teks
Creswell, John W.
Research design : qualitative, quantitative, and mixed methods approaches
Sage, 1994
 Buku Teks