edited by Peter Roberts and Hugh Sykes
Sage, 2003
Buku Referensi
edited by Peter Roberts, Hugh Sykes
Sage Publications, 2003
Buku Referensi
edited by Roy Cresswell
Newnes-Butterworths, 1979
Buku Teks SO
Powell, Kenneth
te Neues, 2000
Buku Teks SO
Simonds, John Ormsbee
McGraw-Hill , 1994
Buku Teks SO