Knellwolf, C., & Norris, C. (2001). Twentieth-century historical, philosophical and psychological perspectives. Cambridge Univ. Press.
Lua i Stíl Chicago (17ú heag.)Knellwolf, Christa, agus Christopher Norris. Twentieth-century Historical, Philosophical and Psychological Perspectives. Cambridge [u.a.]: Cambridge Univ. Press, 2001.
Lua MLA (8ú heag.)Knellwolf, Christa, agus Christopher Norris. Twentieth-century Historical, Philosophical and Psychological Perspectives. Cambridge Univ. Press, 2001.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.