Pender, Nola J.
Appleton & Lange, 1987
Buku Teks SO
Aspen Publication, 1995
Buku Teks
Ducanis, Alex J.
Aspen Publication, 1979
Buku Teks SO
edited by Louise Gallagher, Maryhelen Cole Kreidler
Appletton & Lange, 1987
Buku Teks SO
edited by Hoarst Noack
University Park Press , 1980
Buku Teks SO