A. Asahara, K. Maruyama, A. Sato, and K. Seto. International Conference on Advances in Geographic Information Systems (SIGSPATIAL), page 25--33. New York, NY, USA, ACM, (2011)
M. Becker, H. Mewes, A. Hotho, D. Dimitrov, F. Lemmerich, and M. Strohmaier. International Conference Companion on World Wide Web, page 17--18. Republic and Canton of Geneva, Switzerland, International World Wide Web Conferences Steering Committee, (2016)