Lindlof, Thomas R., author
Sage, 2002
Buku Teks
Holloway, Immy, author
Blackwell Science, 1997
Buku Teks
editors, Norman K. Denzin, Yvonna S. Lincoln
Sage , 2018
Buku Teks
Glazier, Jack D., author
Libraries Unlimited, 1992
Buku Teks
Patton, Michael Quinn, author
Sage, 2002
Buku Teks