Não informado. (1975). Letters in Mathematical Physics. D. Reidel Publishing.
Lua i Stíl Chicago (17ú heag.)Não informado. Letters in Mathematical Physics. Dordrecht, Holanda: D. Reidel Publishing, 1975.
Lua MLA (8ú heag.)Não informado. Letters in Mathematical Physics. D. Reidel Publishing, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.