Ince, D. (Darrel), author
McGraw-Hill, 1995
Buku Teks
edited by Colin Harris, Brian Clifford
British Library, 1985
Buku Teks
Amy Yayuk Sri Rahayu, author
2013
Artikel Jurnal
Sanders, Lalage D., author
BPS Blackwell, 2010
Buku Teks
Filomena Maggino
Springer, 2012
eBooks