Designing location-based mobile games with a purpose: collecting geospatial data with CityExplorer. - Sebastian Matyas; Christian Matyas; Christoph Schlieder; Peter Kiefer; Hiroko Mitarai; Maiko Kamata (Advances in Computer Entertainment Technology, 2008)

CityExplorer - A Geogame Extending the Magic Circle. - Sebastian Matyas; Christian Matyas; Christoph Schlieder; Peter Kiefer (GI Jahrestagung (1), 2008)

A Spatial User Similarity Measure for Geographic Recommender Systems. - Christian Matyas; Christoph Schlieder (GeoS, 2009)

Building Geospatial Data Collections with Location-Based Games. - Sebastian Matyas; Peter Wullinger; Christian Matyas (KI, 2009)

Photographing a City: An Analysis of Place Concepts Based on Spatial Choices. - Christoph Schlieder; Christian Matyas (Spatial Cogn. Comput., 2009)

Geografische Empfehlungssysteme. - Christian Matyas (University of Bamberg Press, 2014)