This stack contains material from the following sources (In german only, contact the publishers for more info.)

Sven Nilsson: Orchids of middle and north Europe Kosmos Stuttgart. Many illustrations.

Parey's book of flowers 2nd rev., Paul Parey Berlin

Publications from W. Frosch about asymbiotic culture of Ophrys and Cypripedium from the Orchid magazine, issue 34+36.

Orchids in the garden, Gerd Kohls/Ulrich Kaehler, Paul Parey Berlin, very good guide for the culture.

Otakar Sadovski, Orchids in the own garden (Sold out).