Hügel, F. (1928). The life of prayer. Dent.
Lua i Stíl Chicago (17ú heag.)Hügel, Friedrich. The Life of Prayer. London: Dent, 1928.
Lua MLA (8ú heag.)Hügel, Friedrich. The Life of Prayer. Dent, 1928.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.