Gödel, Kurt (1949-07-01). "An Example of a New Type of Cosmological Solutions of Einstein's Field Equations of Gravitation". Reviews of Modern Physics. 21 (3): 447–450. doi:10.1103/RevModPhys.21.447. ISSN0034-6861.
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Einstein, Albert (1949). "Einstein's Reply to Criticisms". Albert Einstein: Philosopher-Scientist. Cambridge University Press. Retrieved 29 November 2012.
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Gödel, Kurt (1949-07-01). "An Example of a New Type of Cosmological Solutions of Einstein's Field Equations of Gravitation". Reviews of Modern Physics. 21 (3): 447–450. doi:10.1103/RevModPhys.21.447. ISSN0034-6861.