Boughey, Arthur S., author
Macmillan, 1973
Buku Teks
Spiess, Eliot B., author
John Wiley & Sons, 1977
Buku Teks
Shumway, Waldo, author
John Wiley & Sons, 1954
Buku Teks
Walker, Warren F.
Saunders College Pub., 1986
Buku Referensi
editors, Norman K. Wessells, Elizabeth M. Center
William Kaufmann, 1973
Buku Teks