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