Incremental Topological Mapping Using Omnidirectional Vision. - Christoffer Valgren; Achim J. Lilienthal; Tom Duckett (IROS, 2006)

Probabilistic Semantic Mapping with a Virtual Sensor for Building/Nature detection. - Martin Persson; Tom Duckett; Christoffer Valgren; Achim J. Lilienthal (CIRA, 2007)

SIFT, SURF and Seasons: Long-term Outdoor Localization Using Local Features. - Christoffer Valgren; Achim J. Lilienthal (EMCR, 2007)

Incremental Spectral Clustering and Its Application To Topological Mapping. - Christoffer Valgren; Tom Duckett; Achim J. Lilienthal (ICRA, 2007)

Incremental spectral clustering and seasons: Appearance-based localization in outdoor environments. - Christoffer Valgren; Achim J. Lilienthal (ICRA, 2008)

SIFT, SURF & seasons: Appearance-based long-term localization in outdoor environments. - Christoffer Valgren; Achim J. Lilienthal (Robotics Auton. Syst., 2010)