The Seat of the Soul by Gary Zukav

The Golden Thread by Natalie Banks

The Mysteries Revealed by Andrew Schneider

Bridges by Aart Jurriaanse

Guide to the Mysteries by Ina Crawford

Serving Humanity by Alice Bailey

Ponder on This by Alice Bailey

The Finding of the Third Eye by Vera Stanley Alder

The Challenge for Discipleship by Torkom Saraydarian

Bridge to Superconsciousness by Rick Prater 

Spiritual Politics by Corinne McLaughlin and Gordon Davidson

More Advanced
 

Discipleship in the New Age by Alice Bailey

Initiation Human and Solar by Alice Bailey

Glamour by Alice Bailey

A Treatise on White Magic by Alice Bailey

Esoteric Psychology by Alice Bailey

The Nature of the Soul by Lucille Cedercrans

Leaves of Morya’s Garden by The Agni Yoga Society

The Secret Doctrine by Helena Blavatsky