A lookup to Dirac's Lightcone Coordinate System | Physics Log
PDF] Lensing in the geodesic light-cone coordinates and its (exact) illustration to an off-center observer in Lemaȋtre-Tolman-Bondi models | Semantic Scholar
Eddington–Finkelstein coordinates - Wikiwand
Time Supplement | Internet Encyclopedia of Philosophy
A lookup to Dirac's Lightcone Coordinate System | Physics Log
general relativity - How to interpret the $u',v'$ graph in the Krukal coordinates? how to find the light cone? - Physics Stack Exchange