Butterworth-Heinemann, 2013
eBooks
edited by James Flood, Shirley Brice Heath, and Diane Lapp
MacMillan Library Reference USA, 1996
Buku Referensi
Hongming, Ma
Sense, 2012
eBooks
editor, James R. Newman
Harper & Row, 1963
Buku Referensi
Casti, John L., author
Univesity of East London Library, 1994
Buku Teks