Early evidence of effectiveness of digital contact tracing for SARS-CoV-2 in Switzerland - Marcel Salathé; Christian L. Althaus; Nanina Anderegg; Daniele Antonioli; Tala Ballouz; Edouard Bugnion; Srdjan Čapkun; Dennis Jackson; Sang-Il Kim; James R. Larus; Nicola Low; Wouter Lueks; et al. (Swiss Medical Weekly, 2020)