Water Pollution Control Federation. (1981). WPCF wasterwater treatment skill training package: Anaerobic digestion administration guide. Water Pollution Control Federation.
Lua i Stíl Chicago (17ú heag.)Water Pollution Control Federation. WPCF Wasterwater Treatment Skill Training Package: Anaerobic Digestion Administration Guide. Washington, D.C: Water Pollution Control Federation, 1981.
Lua MLA (9ú heag.)Water Pollution Control Federation. WPCF Wasterwater Treatment Skill Training Package: Anaerobic Digestion Administration Guide. Water Pollution Control Federation, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.