Spontaneous transitions to enhanced fluorescence for GeV centers in a single microcrystalline diamondNatalia A. Lozing, Maxim G. Gladush, Ivan Yu. Eremchev, Eugeniy A. Ekimov and Andrey V. NaumovEPJ Web Conf., 190 (2018) 04012DOI: https://doi.org/10.1051/epjconf/201819004012