Kohler, Heinz
Alfred A. Knoff , 1961
Buku Teks
edited by Paul A. Samuelson
McGraw-Hill, 1970
Buku Teks
Hailstones, Thomas J.
South-Western Publishing, 1974
Buku Teks
Harriss, Clement Lowell, 1912-2009
Prentice-Hall, 1967
Buku Teks
Isaacs, Asher, 1902-1963
Dryden Press, 1952
Buku Teks