Duncan, Peter
Sage, 2014
Buku Teks SO
Hall, George M.
Warren H. Green, 1992
Buku Teks
Harold W. Baillie, John McGeehan, Thomas M. Garrett, Rosellen M. Garrett
Pearson, 2013
Buku Teks SO
Editor: Souzy Dracopoulou
Routledge, 1998
Buku Teks SO
Garrett, Thomas M.
Prentice-Hall, 2001
Buku Teks SO