Energy and Man's Environment. Conservation of energy: Idea and activity guide. Energy and Man's Environment.
Lua i Stíl Chicago (17ú heag.)Energy and Man's Environment. Conservation of Energy: Idea and Activity Guide. Portland, OR: Energy and Man's Environment.
Lua MLA (9ú heag.)Energy and Man's Environment. Conservation of Energy: Idea and Activity Guide. Energy and Man's Environment.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.