Industrial wastewater management handbook
editor-in-chief, Hardam Singh Azad
McGraw-Hill, 1976
 Buku Referensi
Elliot, James
Tourism
Routledge, 1997
 Buku Teks
Tourism
Longman, 1999
 Buku Teks
Cases in Singapore hospitality and tourism management
edited by Hooi Den Huan
Prentice-Hall, 1999
 Buku Teks
Douglas-Young, John
Practical oscilloscope handbook / John Douglas-Young
Parker Publishing Company, 1979
 Buku Referensi