Heart-Wood from the Bo Tree by Buddhadāsa Bhikkhu.

Three talks (“The Essential Points of the Buddhist Teachings,” “Emptiness,” and “The Way to Practice in order to Abide with Emptiness”) given to a Dhamma study group at Siriraj Hospital, Bangkok, on 17^th December 1961 , 7^th and 21^st January 1962.

Translated from the Thai (แก่นพุทธศาสน์) by Dhammavicayo. Suan Usom Foundation, Bangkok, 2528 [1985]. 99 p.