Jardine, J. (1980). Energy. Heinemann Educational.
Lua i Stíl Chicago (17ú heag.)Jardine, Jim. Energy. London: Heinemann Educational, 1980.
Lua MLA (9ú heag.)Jardine, Jim. Energy. Heinemann Educational, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.