A. Tagarev, L. Tolosi, and V. Alexiev. Semantic Keyword-based Search on Structured Data Sources, volume 9398 of Lecture Notes in Computer Science, page 182-196. Springer, (January 2016)First COST Action IC1302 International KEYSTONE Conference (IKC 2015), Coimbra, Portugal, September 8-9, 2015. Revised Selected Papers.
V. Alexiev. Digital Presentation and Preservation of Cultural and Scientific Heritage (DIPP 2018), 8, page 19-50. Burgas, Bulgaria, Institute of Mathematics and Informatics (IMI BAS), Sofia, (September 2018)