Reference:

T. Froehner, M. Nickles, and G. Weiß. Open ontologies – The need for modeling heterogeneous knowledge. In Proceedings of the International Conference on Information and Knowledge Engineering (IKE-2004), 2004.

Suggested BibTeX entry:

@inproceedings{FrNiWe04a,
    author = {T. Froehner and M. Nickles and G. Wei{\ss}},
    booktitle = {Proceedings of the International Conference on Information and Knowledge Engineering (IKE-2004)},
    title = {Open ontologies~-- {T}he Need for Modeling Heterogeneous Knowledge},
    year = {2004}
}