Ehrligh, Ev
Warner Books, 2000
Buku Teks SO
completely rev. and edited by Ingo W.D. Hackin and Claire Grant
McGraw-Hill, 1987
Buku Referensi
Grant, I. S.
John Wiley & Sons, 1975
Buku Teks SO
Grant, Michael, 1914-2004
Penguin Books , [1958]
Buku Teks SO
Gilmore, Grant
The Foundation Press, Inc., 1975
Buku Teks