Feynman, R. P., Sands, M. L., & Penrose, R. (1997). Six not-so-easy pieces: Einstein's relavity, symmetry, and space-time. Perseus Books.
Citazione stile Chigago Style (17a edizione)Feynman, Richard Phillips, Matthew Linzee Sands, e Roger Penrose. Six Not-so-easy Pieces: Einstein's Relavity, Symmetry, and Space-time. Reading: Perseus Books, 1997.
Citatione MLA (9a ed.)Feynman, Richard Phillips, et al. Six Not-so-easy Pieces: Einstein's Relavity, Symmetry, and Space-time. Perseus Books, 1997.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.