C. Kemp, and K. Ramamohanarao. Proceedings of the 6th European Conference on Principles
of Data Mining and Knowledge Discovery (PKDD 2002), page 263--274. Berlin, Springer, (2002)
P. Cimiano, G. Stumme, A. Hotho, and J. Tane. Proceedings of the The Second International Conference on Formal Concept Analysis (ICFCA 04), page 189-207. Springer, (2004)