A. Peres (1962). "On Cauchy's problem in general relativity - II". Nuovo Cimento. Springer. ج. 26 رقم 1. ص. 53–62. DOI:10.1007/BF02754342.
U.H. Gerlach (1968). "Derivation of the Ten Einstein Field Equations from the Semiclassical Approximation to Quantum Geometrodynamics". Physical Review. ج. 177 ع. 5: 1929–1941. Bibcode:1969PhRv..177.1929G. DOI:10.1103/PhysRev.177.1929.
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U.H. Gerlach (1968). "Derivation of the Ten Einstein Field Equations from the Semiclassical Approximation to Quantum Geometrodynamics". Physical Review. ج. 177 ع. 5: 1929–1941. Bibcode:1969PhRv..177.1929G. DOI:10.1103/PhysRev.177.1929.