Laura Romano "Sumarah Spiritual Wisdom from Java" 2013 lulu.com

based on the original Italian version "Sumarah il risveglio del maestro interiore" Ubaldini 1999

Paul Stange "Modern Javanism: The Evolution of Sumarah"

a revision of the PhD dissertation originally entitled "The Sumarah Movement in Javanese Mysticism", 1980