Steven Duplij, Supergravity was discovered by D.V. Volkov and V.A. Soroka in 1973, wasn’t it?, East Eur. J. Phys., v3, p. 81-82 (2019) (Journal version), (arXiv:1910.03259) Precursor discussion of supergravity (D=4 supergravity): On D=4 supergravity formulated in superspace: On the history of supergravity: