Helmer, C. (2004). Schleiermacher and Whitehead: Open systems in dialogue. Walter de Gruyter.
Lua i Stíl Chicago (17ú heag.)Helmer, Christine. Schleiermacher and Whitehead: Open Systems in Dialogue. Berlin ; New York: Walter de Gruyter, 2004.
Lua MLA (9ú heag.)Helmer, Christine. Schleiermacher and Whitehead: Open Systems in Dialogue. Walter de Gruyter, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.