Vold, George B. (George Bryan), 1896-1967
Oxford University Press, 1979
Buku Teks
Adler, Freda
McGraw-Hill, 1991
Buku Teks
Siegel, Larry J., 1959-
Wadsworth and Cengage Learning, 2012
Buku Teks
Adler, Freda
McGraw-Hill, 1998
Buku Teks
Taft, Donald R.
Macmillan, 1964
Buku Teks