Feynman, R. P. (1997). Six not so easy pieces: Einsteinïs relativity, symmetry, and space-time. Basic Book.
Dyfyniad Arddull ChicagoFeynman, Richard Phillips. Six Not so Easy Pieces: Einsteinïs Relativity, Symmetry, and Space-time. Nueva York: Basic Book, 1997.
Dyfyniad MLAFeynman, Richard Phillips. Six Not so Easy Pieces: Einsteinïs Relativity, Symmetry, and Space-time. Basic Book, 1997.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.