TY  - RPRT
TI  - Curvature Element Transformations Which Preserve Integrable Fields.
AU  - E Kasner
AU  - J De Cicco
PY  - 1939
DO  - 10.1073/pnas.25.2.104
UR  - https://pubmed.ncbi.nlm.nih.gov/16588267/
ID  - 16588267
ER  -