Anderson, Owen J.
Cambridge University Press, 2012
Buku Teks SO
Tilley, Christopher Y.
Routledge, 1991
Buku Teks
Garland, Henry
Oxford University Press, 1995
Buku Referensi
Bosacki, Sandra Leanne
Sense, 2012
eBooks
Weston, Michael
Routledge, 2001
Buku Teks SO