Grossmann, R. (1990). The Fourth Way: A Theory of Knowledge. Indiana University Press.
Lua i Stíl Chicago (17ú heag.)Grossmann, Reinhardt. The Fourth Way: A Theory of Knowledge. Bloomington: Indiana University Press, 1990.
Lua MLA (9ú heag.)Grossmann, Reinhardt. The Fourth Way: A Theory of Knowledge. Indiana University Press, 1990.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.