@book{Dykstra2009a,
author = "Dykstra, P.",
title = "Intergenerational relationships in ageing societies",
year = 2009,
journal = "United Nations Economic Commission for Europe Working Group on Ageing",
publisher = "United Nations",
volume = ECE/WG.1/2009/3, 1-4,
url = "http://www.unece.org/pau/pub/ageing_intergenerational_relationships_2010.html"
}