Graf, Simone;Engelmann, Luca;Jeleff Wölfler, Olivia;Albrecht, Inka;Schloderer, Matthias;Kramer, Anna;Klankermayer, Lucia;Gebhardt, Friedemann;Chaker, Adam M;Spinner, Christoph D;Schwab, Roland;Wollenberg, Barbara;Protzer, Ulrike;Hoffmann, Dieter Reopening the Bavarian State Opera Safely: Hygiene Strategies and Incidence of COVID-19 in Artistic Staff During Theater Season 2020/2021. J Voice 2024 38 3 798.e7-798.e20