Denbigh, Kenneth, author
Cambridge University Press, 1961
Buku Teks
Majalah, Jurnal, Buletin
Van Nostrand Reinhold, 1977
Buku Teks
Clarke, L.J.
John Wiley & Sons, 1985
Buku Teks
edited by Jan Vincents Johannessen
McGraw-Hill Internanational Book Company, 1995
Buku Referensi