A Special Class of Solutions of the Equations of the Gravitational Field Arising from Certain Gauge-Invariant Action Principles
- 1 February 1948
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 34 (2) , 66-68
- https://doi.org/10.1073/pnas.34.2.66