Atkins, Ruth
"John Willey ,
Buku Teks
Atkins, Ruth
John Wiley & Sons, 1972
Buku Teks SO
Ranny, Austin
Prentince-Hall, 1987
Buku Teks
W. Neil Adger, editor
Cambridge University Press, 2009
Buku Teks
Cook, Timothy E.
The University of Chicago Press, 1997
Buku Teks SO