Leary, Timothy (1997). Über die Kriminalisierung des Natürlichen (in German). Löhrbach: Werner Pieper’s Medienexperimente. ISBN3-925817-38-7.
Amendt, Günter (2004). No Drugs. No Future. Drogen im Zeitalter der Globalisierung (in German). Zweitausendeins. ISBN3-86150-625-4.
McKenna, Terence (1998). Non-Ordinary States Through Vision Plants. Mill Valley CA.: Sound Photosynthesis. ISBN1-569-64709-7. We're playing with half a deck as long as we tolerate that the cardinals of government and science should dictate where human curiousity can legitimately send its attention and where it can not. It's an essentially preposterous situation. It is essentially a civil rights issue, because what we're talking about here is the repression of a religious sensibility. In fact, not a religious sensibility, the religious sensibility.