RICHARDS, R. (1991). An Early Start To Ourselves And Evolution With Life Processes Roy Richards. Simon and Schuster.
Lua i Stíl Chicago (17ú heag.)RICHARDS, Roy. An Early Start To Ourselves And Evolution With Life Processes Roy Richards. Simon and Schuster, 1991.
Lua MLA (8ú heag.)RICHARDS, Roy. An Early Start To Ourselves And Evolution With Life Processes Roy Richards. Simon and Schuster, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.