Kolstee, Hans M.
Holt, Rinehart and Winston, 1985
Buku Teks
Hall, Allen S., author
McGraw-Hill International Book Company, 1983
Buku Teks
Singh, Balbir
Vikas Publishing House, 1982
Buku Teks
Johnson, Ray C., author
John Wiley & Sons, 1980
Buku Teks
Lingaiah, K., author
McGraw-Hill, 1994
Buku Referensi