Reference for the questionnaire:
Kadesjö, B., Janols. L-O, Korkman, M., Mickelsson, K., Strand, G., Trillingsgaard, A., Lambek, R., Øgrim, G., Bredesen, A. M., & Gillberg, C. (2017). Five-To-Fifteen-Revised (5-15R). Available at www.5-15.org
 
Copyright © (2004): Björn Kadesjö, Göteborg, Lars-Olof Janols, Uppsala, Marit Korkman, Helsingfors, Katarina Mickelsson, Helsingfors, Gerd Strand, Oslo, Anegen Trillingsgaard, Århus, Christopher Gillberg, Göteborg. The Copyright is protected under the Swedish Copyright Act – the Swedish law Act on Copyright in Literary and Artistic Works (1960:729).