The Mahatma Letters to A.P. Sinnett

The Mahatma Letters to A.P. Sinnett is a book published in 1923 by A. Trevor Barker. (ISBN 1-55700-086-7) According to Theosophical teachings, the letters were written between 1880 and 1884 by Koot Hoomi and Morya to A. P. Sinnett.

Source: Wikipedia — The Mahatma Letters to A.P. Sinnett (CC BY-SA 4.0)