The Gain of Failures: Using Side-Effects of Anaphora Resolution for Term Consistency Checks. - Galia Angelova; Ognian Kalaydjiev; Walther von Hahn (AIMSA, 1998)

Integration of Resources and Components in a Knowledge-Based Web-Environment for Terminology Learning. - Svetla Boytcheva; Ognian Kalaydjiev; Ani Nenkova; Galia Angelova (AIMSA, 2000)

An Intelligent Pedagogical Agent in CALL. - Ognian Kalaydjiev (User Modeling, 2001)

Adaptivity in Web-Based CALL. - Galia Angelova; Svetla Boytcheva; Ognian Kalaydjiev; Stefan Trausan-Matu; Preslav Nakov; Albena Strupchanska (ECAI, 2002)

Domain Ontology as a Resource Providing Adaptivity in eLearning. - Galia Angelova; Ognian Kalaydjiev; Albena Strupchanska (OTM Workshops, 2004)

From Conceptual Structures to Semantic Interoperability of Content. - Pavlin Dobrev; Ognian Kalaydjiev; Galia Angelova (ICCS, 2007)