In reading a book by Andrew Holecek, 'Dream Yoga' I came across a paragraph in the "Eastern LD induction techniques" section where he is talking about the lotus visualization.

He mentions an man named PD Ouspensky, and him writing about having a technique where he could voluntarily enter a lucid dream from a waking state.
Does anyone know what he is referring to? Ouspensky has so many books I do not even know where to begin.