Regular and Problematic Leisure-Time Internet Use in the Community: Results from a German Population-Based Survey. - Manfred E. Beutel; Elmar Brähler; Heide Glaesmer; Daria J. Kuss; Klaus Wölfling; Kai W. Müller (Cyberpsychology Behav. Soc. Netw., 2011)

Prevalence of internet addiction in the general population: results from a German population-based survey. - Kai W. Müller; Heide Glaesmer; Elmar Brähler; Klaus Wölfling; Manfred E. Beutel (Behav. Inf. Technol., 2014)