Heintz, James A., author
Thomson/South-Wester, 2005.
Buku Teks
Heintz, James A., author
South-Western Publishing, 1990
Buku Teks
Barrdell, Ross H., author
Addison-Wesley, 1953
Buku Teks
Beckenbach, Edwin F., author
Wadsworth, 1964
Buku Teks
Smith, Karl J., author
Brooks/Cole, 1985
Buku Teks