1. Agrawal, R., Imielinski, T., Swami, A.: Mining association rules between sets of items in large databases. In: Proc. ACM Int’l Conf. on Management of Data, pp. 207–216 (1993)
2. Balcázar, J.L., Bifet, A., Lozano, A.: Mining frequent closed rooted trees. Machine Learning 78(1-2), 1–33 (2010)
3. Borgelt, C.: On Canonical Forms for Frequent Graph Mining. In: Workshop on Mining Graphs, Trees, and Sequences (MGTS), pp. 1–12 (2005)
4. Borgelt, C., Berhold, M.R.: Mining molecular fragments: finding relevant substructures of molecules. In: Proc. of 2002 IEEE Int. Conf. on Data Mining (ICDM), pp. 51–58 (2002)
5. Chartrand, G., Zhang, P.: Introduction to Graph Theory. McGraw Hill, New York (2002)