1. AlKhatib W. Robbins M. Shteiwi M.et al. (2016)Arab Barometer: Public Opinion Survey Conducted in Algeria Egypt Jordan Lebanon Morocco Palestine and Tunisia 2016: Methodology. Available from:https://www.icpsr.umich.edu/icpsrweb/ICPSR/studies/37029/datadocumentation
2. Immigrant selection in the OECD;Belot M.V.K.;The Scandinavian Journal of Economics,2012
3. Signals and closure by degrees: The education effect across 15 European countries;Bol T.;Research in Social Stratification and Mobility,2011