Stotlar, David K
Brown and Benchmark, 1993
Buku Teks
edited by Edward C. Bursk and John F. Chapman
New American Library, 1964
Buku Teks
Kelley, Eugene J.
Prentice-Hall, 1965
Buku Teks
Markin, Rom J.
John Wiley & Sons, 1982
Buku Teks
Thorelli, H.B.
Penguin Books, 1973
Buku Teks