Schumann, Walter
Gemstones of the world
Sterling, 1997
Buku Referensi
Natural stone : a guide to selection / Studio Marmo ; text by Frederick Bradley
W.W. Norton & Company, Inc, 1998
Buku Teks
Reclaiming universities from a runaway world
Open University Press, 2004
Buku Teks
Junkovsky, N.
Conveying, crushing, washing and screening machinery / N. Junkovsky; translated from the Russian by David Sobolev
Mir Publishers, 1966
Buku Teks
Jensen, Bernard
Dr. Jensen's Nature Has a Remedy : Healthy Secrets From Around the World
Keats Publishing, 2000
Buku Teks