Bell, Judith, author
McGraw-Hill Education, 2014
Buku Teks
McGraw-Hill, 2012
Buku Teks
Bell, Judith, author
Open University Press, 1993
Buku Teks
Creswell, John W., author
Pustaka Pelajar, 2017
Buku Teks
Black, James A., author
John Wiley & Sons, 1976
Buku Teks