Lunar Returns:
Lunar Returns unlock the mysteries of everyday events
by John Townley

This is a personal favorite because Maria includes David's original tune, "Become the Deliverer: Follow the Moon to the Sun."

Moon Tides, Soul Passages:
Uses astrology and Goddess mythology to reveal meaning in the patterns of the Moon
by Maria Kay Simms

The Nature of Personal Reality:
We first read this book in the 70's and its message holds up after 30 years
by Jane Roberts

God Is No Laughing Matter:
Observations and Objections on the Spiritual Path
by Julia Cameron