@workingPaper{BaaderBürckertHollunderNuttSiekmann_1990, title={Concept logics}, author={Baader, Franz and Bürckert, Hans-Jürgen and Hollunder, Bernhard and Nutt, Werner and Siekmann, Jörg H.}, doi={http://dx.doi.org/10.22028/D291-24904}, year={1990} }