edited by Sybil P. Parker
McGraw-HIll, 1995
Buku Referensi
Columbia University Press, 1949
Buku Teks SO
Browne, G.S.
F.W. Chesire, 1960
Buku Teks
James, Preston E.
John Wiley & Sons, 1980
Buku Teks SO
by Christopher L. Salter ... [et al.]
Saunders College Publishing, 2000
Buku Teks SO