Barry, Roger D., author
Bobbs Merrill, 1975
Buku Teks
Fessenden, Ralph J., author
Wilard Grant Press, 1979
Buku Teks
Baker, A. David, author
West Publishing, 1992
Buku Teks
English, James, author
McGraw-Hill, 1956
Buku Teks
Griffin, Rodger W., author
McGraw-Hill, 1969
Buku Teks