“…Work in this domain has been encouraged through evaluation campaigns, first through the NII 10 Test Collection for IR Systems (NTCIR) [57,60,93,145,146], and later through the Text Retrieval Conference (TREC) (for the chemical domain [129]) and continuing at the moment of writing this review, through the Cross-Language Evaluation Forum (CLEF) [156,157,158,161].…”