Speziale, Helen J. Streubert, author
J.B. Lippincott , 1995
Buku Teks
edited by Else Oyen
Sage, 1992
Buku Teks
Foddy, William, author
Cambridge University Press, 1993
Buku Teks
Townsend, Peter, author
Pinguin Book, 1975
Buku Teks
Neuman, William Lawrence, 1950-, author
Pearson, 2014
Buku Teks