Roß T, Reinke A, Full PM, Wagner M, Kenngott H, Apitz M, Hempe H, M\^ındroc-Filimon D, Scholz P, Tran TN, et al. Comparative validation of multi-instance instrument segmentation in endoscopy: Results of the ROBUST-MIS 2019 challenge. Medical Image Anal. [Internet]. 2021;70:101920.