Kalama Sutta: The Buddha's Charter of Free Inquiry, translated from the Pali by Soma Thera (Buddhist Publication Society Wheel Publication No. 8; 1981; 20k/6pp.)
In this famous and important discourse the Buddha sets forth a standard by which a seeker can evaluate any spiritual path. With preface and supplementary texts. (For an illuminating commentary on this sutta, see Bhikkhu Bodhi's essay, "A Look at the Kalama Sutta.")
The Removal of Distracting Thoughts, by Soma Thera (Buddhist Publication Society Wheel Publication No. 21; 1981; 46k/15pp.)
Translation of the Vitakkasanthana Sutta (Majjhima Nikaya 20) and its Commentary (the Papañcasudani).
The Way of Mindfulness: The Satipatthana Sutta and Its Commentary, by Soma Thera (1999; 440k/147pp.)
A translation of the Satipatthana Sutta, the Discourse on the Foundations of Mindfulness, together with its classical commentaries. This handbook contains a wealth of essential source material for the practice of insight meditation.
Words Leading to Disenchantment & Samsara: Two Essays, by Soma Thera (Buddhist Publication Society Bodhi Leaves No. 79; 1978; 24k/8pp.)
These two short essays invite us to reflect constantly on the certainty of our own death and on the urgency of putting the Buddha's teachings into practice today, while we can still enjoy this precious human birth. For "truly it will be not long before this body lies in the earth, bereft of consciousness, like a useless piece of wood, which is thrown away."