Optically targeted search for gravitational waves emitted by core-collapse supernovae during the first and second observing runs of advanced LIGO and advanced Virgo
B.~P. Abbott, R. Abbott, T.~D. Abbott, S. Abraham, F. Acernese, K. Ackley, C. Adams, V.~B. Adya, C. Affeldt, et al
April 2020