The tradition of these guhya or secretive Bhairava is really an oral tradition that is continuous from the guru disciple tradition. Their karmakand rituals and techniques are mystery, they aren't written down but only learnt and practiced in Expert disciple tradition. One of many oldest and holy towns of India, https://prxdirectory.com/listings13069565/kaal-bhairav-things-to-know-before-you-buy