5Eva Bernhardt:"Cohabitation or marriage? Preferred living arrangements in Sweden" See http://www.oif.ac.at/sdf/sdf04-04-bernhardt.pdf.
6Anne -Marie Ambert:"Cohabitation not equal to marriage "Vanier study reports Oct 24,2005.
7Catherine Fitch,Ron Goeken and Steven Ruggles:"The Rise of Cohabitation in the United States:New Historical Estimates" Minnesota Population Center University of Minnesota March 2005; David Popenoe Barbara Dafoe Whitehead:"Life Without Children" July,2006.
10Dr.Robert Wintemute:Levels of recognition of different-sex and same-sex partnerships School of Law,King's College,University of London,see http://www.lsvd.de/bund/lpartg/uebersicht.html.