Budd, Thomas A.
Alexander Hamilton Institute, 1961
Buku Teks
White, Gerald I.
John Wiley & Sons, 1994
Buku Teks
Fraser, Lyn M.
Prentice-Hall International, 1995
Buku Teks
Friedlob, G. Thomas
Barron's Educational Series, 1991
Buku Teks
McMullen, Stewar Yarwood
Richard D. Irwin, 1979
Buku Teks