edited by Robin Osborne and Jeremy Tanner
Blackwell Publishing, 2007
Buku Teks
Infold, Tim, 1948, author
Routledge, 2013
Buku Teks
Crisp, Barbara, author
Rockport Publishers, 1998
Buku Referensi
: Processing Directorate Pertamina, 1998
Buku Teks
Pathak, Haresh, author
The Pepin Press, 1999
Buku Referensi