Theobald, D. W. (1966). The Concept of energy. E & F N. Spon Ltd.
Lua i Stíl Chicago (17ú heag.)Theobald, David W. The Concept of Energy. London: E & F N. Spon Ltd, 1966.
Lua MLA (9ú heag.)Theobald, David W. The Concept of Energy. E & F N. Spon Ltd, 1966.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.