Giant fine structure splitting of the bright exciton in a bulk MAPbBr3 single crystal by Baranowski, M, Galkowski, K, Surrente, A, Urban, JM, Klopotowski, Ł, Mackowski, S, Maude, DK, Aich, R, Boujdaria, K, Chamarro, M, Testelin, C, Nayak, P, Dollmann, M, Snaith, HJ, Nicholas, RJ, Plochocka, P