BioASQ: A challenge on large-scale biomedical semantic indexing and question answering

George Tsatsaronis, Michael Schroeder, Georgios Paliouras, Yannis Almirantis, Ion Androutsopoulos, Eric Gaussier, Patrick Gallinari, Thierry Artieres, Michael R. Alvers, Matthias Zschunke, Axel Cyrille Ngonga Ngomo