Edwards, P. (2004). Mailed questionnaires: Length matters.
Lua i Stíl Chicago (17ú heag.)Edwards, P. Mailed Questionnaires: Length Matters. 2004.
Lua MLA (9ú heag.)Edwards, P. Mailed Questionnaires: Length Matters. 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.