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Ryynänen OP, Kivelä SL, Honkanen R, Laippala P.Ryynänen OP, et al.Scand J Prim Health Care. 1992 Dec;10(4):277-83. doi: 10.3109/02813439209014074.Scand J Prim Health Care. 1992.PMID: 1480867
Ryynänen OP, Myllykangas M, Viren M, Heino H.Ryynänen OP, et al.Public Health. 2002 Nov;116(6):322-31. doi: 10.1038/sj.ph.1900875.Public Health. 2002.PMID: 12407471