Artikel Jurnal
by Andrew Schmitz, P. Lynn Kennedy, Troy G. Schmitz
Emerald, 2017
eBooks
editor, Rattan Lal, B.A. Stewart
CRC Press, 2012
Buku Teks
edited by Jose L. Tadeo
CRC Pres, 2008
Buku Teks
Lee Harrison, editor in chief
McGraw-Hill, 1995
Buku Referensi