Naqshbandiyya-Mujaddidiyya Order of Sufism. Naqshbandi Sufis are known as the "silent Sufis" because they practice the silent meditation of the heart. Meditation groups worldwide. Inverness, California.

Courses, workshops and tapes of meditations for spiritual growth channelled by Christopher Sell. Northumberland, England, UK.

Offers online instruction, workshops and retreats in heart-centered meditation. Includes articles on the technique and its effects on achievements, relationships, and health.

A nonprofit research and education organization offering prevention and intervention strategies for improved emotional health, decision-making, learning skills and violence reduction in families, schools and communities.