F. Suchanek, G. Kasneci, and G. Weikum. Proceedings of the 16th International Conference on World Wide Web, page 697--706. New York, NY, USA, ACM, (2007)
M. Mladenov, L. Kleinhans, and K. Kersting. Proceedings of the 31st AAAI Conference on Artificial Intelligence (AAAI), (2017)Preprint available at https://arxiv.org/abs/1606.04486.