TY  - RPRT
TI  - Fermat's principle in general relativity.
AU  - R Nityananda
AU  - J Samuel
PY  - 1992
DO  - 10.1103/physrevd.45.3862
UR  - https://pubmed.ncbi.nlm.nih.gov/10014279/
ID  - 10014279
ER  -