(1989). Metode Penelitian Survai. LP3ES.
Lua i Stíl Chicago (17ú heag.)Metode Penelitian Survai. LP3ES, 1989.
Lua MLA (8ú heag.)Metode Penelitian Survai. LP3ES, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)