Neuman, William Lawrence, 1950-
Social research methods: qualitative and quantitative approaches
Allyn and Bacon, 2003
 Buku Teks
Neuman, William Lawrence, 1950-
Social research methods: qualitative and quantitative approaches
Allyn and Bacon, 2000
 Buku Teks
Creswell, John W.
Research design : qualitative, quantitative, and mixed methods approaches
Sage Publication, Inc, 2003
 Buku Teks
Neuman, William Lawrence, 1950-
Social research methods: qualitative and quantitative approaches
Allyn and Bacon, 1994
 Buku Teks
Creswell, John W.
Research design : qualitative, quantitative, and mixed methods approaches
Sage, 2014
 Buku Teks