(1979). Environmental Health criteria 9.
Lua i Stíl Chicago (17ú heag.)Environmental Health Criteria 9. 1979.
Lua MLA (9ú heag.)Environmental Health Criteria 9. 1979.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.
Lua APA (7ú heag.)