TY  - RPRT
TI  - Knot theory and quantum gravity.
AU  - C Rovelli
AU  - L Smolin
PY  - 1988
DO  - 10.1103/physrevlett.61.1155
UR  - https://pubmed.ncbi.nlm.nih.gov/10038716/
ID  - 10038716
ER  -