Carmines, E. G., & Zeller, R. A. (1979). Reliability and validity assessment. Sage.
Lua i Stíl Chicago (17ú heag.)Carmines, Edward G., agus Richard A. Zeller. Reliability and Validity Assessment. Beverly Hills, Calif: Sage, 1979.
Lua MLA (9ú heag.)Carmines, Edward G., agus Richard A. Zeller. Reliability and Validity Assessment. Sage, 1979.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.