Digital Libraries for Open Knowledge 23rd International Conference on Theory and Practice of Digital Libraries, TPDL 2019, Oslo, Norway, September 9-12, 2019, Proceedings - Doucet, Antoine; Doucet, Antoine; Isaac, Antoine; Isaac, Antoine; Golub, Koraljka; Golub, Koraljka; Aalberg, Trond; Aalberg, Trond; Jatowt, Adam; Jatowt, Adam (Springer International Publishing : Imprint: Springer, 2019)