Danielle A.I. Groffen. Material Versus Psychosocial Explanations of Socioeconomic Differences in Health-Related Function in Older People. Proefschrift. Maastricht: Universitaire Pers Maastricht, 2011. 158 P. TGG 2012, No. 1. https://doi.org/10.1007/s12439-012-0007-z.