edited by Gillian M. McCombs
The Haworth Press, 1991
Buku Teks SO
Ball, David
Facet Publishing, 2005
Buku Teks SO
edited by Allan McNaught
Chapman and Hall , 1991
Buku Teks
Cricket Liu; Jerry Peek; Russ Jones; Bryan Buus; Adrian Nye
O'Reilly, 1994
Buku Teks SO
Goodwin, Nick
McGraw-Hill Open Univ. Press, 2006
Buku Teks