Literature
I prefer the follow books and journals:
Hermann R. Sweet 'The Genus Phalaenopsis'
Orchid Digest, Orchid of the World Volume 1, 1980
Olaf Gruss / Manfred Wolff 'Phalaenopsis'
Publisher: Verlag Eugen Ulmer, Stuttgart 1995
Eric A. Christenson 'Phalaenopsis - A Monograph'
Timber Press, Inc., Portland, Oregon, 2001
Chiba Masaaki 'Phalaenopsis Species'
Chiba Masaaki Phalaenopsis Species Publishing Society, Sakado, Saitama (Japan), 2002
Orchid Digest Vol. 66 (4), Phalaenopsis
The Orchid Digest Corporation, 2002