Kahn, Alfred J., author
Russel Sage Foundation, 1969
Buku Teks
Sheafor, Bradford W., author
Allyn and Bacon, c2000
Buku Teks
Steward, Elbert W
McGraw-Hill, 1972
Buku Teks
Schottland, Charles I.
Appleton-Century-Crofts, 1963
Buku Teks
by Thomas L. Hartshorne ... [and others]
Longman, 2003
Buku Teks