Freund, P. A. (1972). Experimentation with human subjects. Allen and Unwin.
Lua i Stíl Chicago (17ú heag.)Freund, Paul A. Experimentation with Human Subjects. London: Allen and Unwin, 1972.
Lua MLA (8ú heag.)Freund, Paul A. Experimentation with Human Subjects. Allen and Unwin, 1972.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.