Historical transformations of techniques for overcoming performance anxiety in the context of professional training of a modern vocalistNatalia Nikulina, Nataliya Buyanova, Olga Orekhova, Irina Rubcova and Diana ShnurovaE3S Web Conf., 210 (2020) 18123DOI: https://doi.org/10.1051/e3sconf/202021018123