Book: Liber 206 Ru Vel Spiritus by Aleister Crowley
Full Instructions in Pranayama, describes various practices of controlling the breath, how to insure success, what results to strive for, and how to use them for the Great Work. Equinox I vii, p. 59Books in PDF format to read:
Aleister Crowley - Liber 850 Vel Rites Of EleusisAleister Crowley - Liber 412 A Vel Armorum
Aleister Crowley - Liber 009 E Vel Exercitiorum
Aleister Crowley - Liber 570 Vel Ararita
Aleister Crowley - Liber 206 Ru Vel Spiritus