Fernandez-Berni, Jorge
[, Springer], 2012
eBooks
Hill, Robert J.
Macmillan, 1982
Buku Referensi
Mueller, Conrad G.
Time Incoporated, 1966
Buku Teks SO
Ballard, Dana H.
Prentice-Hall, 1982
Buku Teks
edited by Richard L. Cherry, Robert J. Conley and Bernard A. Hirsch
Houghton Mifflin, 1974
Buku Teks SO