Rovelli, C (1993). "Statistical mechanics of gravity and the thermodynamical origin of time". Classical and Quantum Gravity. 10 (8). IOP Publishing: 1549–1566. Bibcode:1993CQGra..10.1549R. doi:10.1088/0264-9381/10/8/015.
Rovelli, C (1993). "Statistical mechanics of gravity and the thermodynamical origin of time". Classical and Quantum Gravity. 10 (8). IOP Publishing: 1549–1566. Bibcode:1993CQGra..10.1549R. doi:10.1088/0264-9381/10/8/015.