Although this is off topic to what this forum is all about, I'll try to give you as much information as I know. First, sleep learning was first developed in eastern europe in the '50s-'60s. It is based on the well established fact nowadays that learning is best done when the brain is in a predominantly alpha state (deeply relaxed but still conscious, 8-13 hz), that is, just before you doze off, otherwise known as stage 2 sleep. Sleep learning has just about dissapeared these days because of the new learning technologies (like the ones LS offers). Many of the new technologies advocate acheiving an alpha state before the learning session begins through various means (binaural encoded tapes, relaxation exercises, mind machines, etc...). I doubt you'll find much out there for sleep learning, the closest thing I can think of is Nova Dreamer. Try
WWW.lucidity.com. Be cool! 
