Merikukka, Marko, Tiina Ristikari, Reija Paananen, and Mika Gissler. 2017. “Investigating the Incidence of Youth Mental Health Problem by Merging Person Register and School Level Class Room Survey Data: IJPDS (2017) Issue 1, Vol 1:265 Proceedings of the IPDLN Conference (August 2016)”. International Journal of Population Data Science 1 (1). https://doi.org/10.23889/ijpds.v1i1.285.