Ontology-Based Retrieval of Experts - The Issue of Efficiency and Scalability within the eXtraSpec System - Bukowska, Elzbieta; Kaczmarek, Monika; Stolarski, Piotr; Abramowicz, Witold (Multidisciplinary Research and Practice for Information Systems - IFIP WG 8.4, 8.9/TC 5 International Cross-Domain Conference and Workshop on Availability, Reliability, and Security, CD-ARES 2012, Prague, Czech Republic, August 20-24, 2012. Proceed, 2012)