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Practical Insight Meditation – Mahasi Sayadaw

The Progress of Insight (Visuddhi├▒ana-katha) – Mahasi Sayadaw

The Sixteen Stages of Insight – Phra Dhamma Theerarach Mahamuni

For Purchase (Amazon Links):

Mastering the Core Teachings of the Buddha – Daniel Ingram

The Science of Enlightenment: How Meditation Works – Shinzen Young

Radical Acceptance: Tara Brach