Jonas Edlund, и Mikael Stattin. Older Workers in an Ageing Society: Critical Topics in Research and Policy, Edward Elgar Publishing, Cheltenham, (ISSP).(2013)
V. Havasi. Social Indicators Research, 113 (1):
17-35(2013)First published online: August 03, 2011, http://dx.doi.org/10.1007/s11205-011-9901-y. (Eurobarometer).