Vane, Edwin T
Focall Press, 1994
Buku Teks
Gross, Lynne Schafer
Iowa WCB , 1989
Buku Teks
Eastman, Susan Tyler, author
Wadsworth, 1985
Buku Teks
Ahuja, B. N., author
Surjeet Publications, 1990
Buku Teks
Beville, Hugh Malcolm
Lawrence Erlbaum Associates, 1985
Buku Teks