@article {1568594, title = {Constraints on non-Einsteinian black-hole charges with the 2019 EHT observations of M87}, journal = {Physical Review D}, volume = {103}, number = {10}, year = {2021}, month = {2020}, pages = {40-47}, url = {https://journals.aps.org/prd/abstract/10.1103/PhysRevD.103.104047}, author = {Prashant Kocherlakota and Luciano Rezzolla and Event Horizon Telescope Collaboration} }