Social Class
        Beere, Paul, Keeling, Sally, Jamieson, Hamish 2019. Ageing, loneliness, and the geographic distribution of New Zealand's interRAI-HC cohort. Soc Sci Med.  227 () 84-92.  
          Hirdes, J. P., Strain, L. A. 1995. The balance of exchange in instrumental support with network members outside the household. Journals of Gerontology Series B-Psychological Sciences & Social Sciences.  50 (3) S134-42.