Read Andy's own article about the sticky note he found on his car: https://innerouter.info/content/sticky-note
Andy mentions:
Living with the Himalayan Masters: https://www.rishikulyogshala.org/assets/books/living-with-the-himalayan-masters.pdf
Swami Rama: https://himalayaninstitute.org/online/teachers/swami-rama/
Autobiography of a Yogi by Paramhansa Yogananda https://www.freespiritualebooks.com/autobiography-of-a-yogi.html?gad_source=1&gad_campaignid=14120536211&gbraid=0AAAAABOYGz--KbMWbfGiGusndi_hEFvEJ&gclid=Cj0KCQjwxdXBBhDEARIsAAUkP6hJGL1XZIQ4Vnj55KxUjpQ-MjEi8lztnC-NQ93g8sGtpjhbk22jgZAaAktOEALw_wcB
Dannion Brinkley https://dannion.com/
The Great Approach, by Benjamin Creme https://share-ecart.com/the-great-approach/
Maitreya https://share-international.org/in-depth/maitreya/
the Masters of Wisdom https://share-international.org/in-depth/masters-of-wisdom/
Share International magazine https://share-international.org/resources/magazine/
Transmission Meditation https://share-international.org/in-depth/transmission-meditation/
the Ageless Wisdom Teaching https://share-international.org/in-depth/ageless-wisdom-teaching/
Alice A. Bailey https://www.lucistrust.org/books/about_alice_a_bailey
Helena Roerich https://en.icr.su/family/hir/
the Agni Yoga teachings https://agniyoga.org/
the Sword of Cleavage https://share-international.org/resources/articles/the-sword-of-cleavage/