Rieker, Hans-Ulrich. The secret of meditation [by] Hans-Ulrich Rieker; translated from the German by A. J. Pomerans. - London: Rider, 1974 - 176 p.; 22 cm. Translation of Das Geheimnis der Meditation. ISBN: 0091188415 Subjects--Topical Terms: Meditation. Dewey Class. No.: 291.3 / RIE