Marshall, Catherine, author
Sage, 1999
Buku Teks
Silverman, David, author
Buku Teks
Walle, Alf H., author
Quorum Books, 2001
Buku Teks
Green, Judith, 1961-, author
Sage, 2018
Buku Teks
edited by Norman K. Denzin, Yvonna S. Lincoln
Sage, 2011
Buku Referensi