@ARTICLE{
author={Hatala Marek,Gasevic Dragan,Siadaty Melody,Jovanovic Jelena M,Torniai Carlo},
year={2012},
title={Ontology Extraction Tools: An Empirical Study with Educators},
journal={IEEE TRANSACTIONS ON LEARNING TECHNOLOGIES},
volume={5},
number={3},
pages={275-289},
document_type={Article},
} 

@ARTICLE{
author={Gasevic Dragan,Zouaq Amal,Torniai Carlo,Jovanovic Jelena M,Hatala Marek},
year={2011},
title={An Approach to Folksonomy-Based Ontology Maintenance for Learning Environments},
journal={IEEE TRANSACTIONS ON LEARNING TECHNOLOGIES},
volume={4},
number={4},
pages={301-314},
document_type={Article},
} 

@ARTICLE{
author={Jovanovic Jelena M,Gasevic Dragan,Torniai Carlo,Bateman Scott,Hatala Marek},
year={2009},
title={The Social Semantic Web in Intelligent Learning Environments: state of the art and future challenges},
journal={INTERACTIVE LEARNING ENVIRONMENTS},
volume={17},
number={4},
pages={273-309},
document_type={Article},
}