TRYFOS, P. (1996). Sampling methods for applied research: Text and cases. John Wiley and Sons.
Lua i Stíl Chicago (17ú heag.)TRYFOS, Peter. Sampling Methods for Applied Research: Text and Cases. New York: John Wiley and Sons, 1996.
Lua MLA (9ú heag.)TRYFOS, Peter. Sampling Methods for Applied Research: Text and Cases. John Wiley and Sons, 1996.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.