Jabarkan Tempo ogé dari Énergi dalam bahasa sunda

Feynman, Richard. Six Easy Pieces: Essentials of Physics Explained by Its Most Brilliant Teacher. Helix Book. See the chapter "conservation of energy" for Feynman's explanation of what energy is and how to think about it.

Einstein, Albert (1952). Relativity: The Special and the General Theory (Fifteenth Edition). ISBN 0-517-88441-0