@techreport{Hagen-Zaker2008,
author = {Hagen-Zaker, J.},
title= {Why do people migrate? A review of the theoretical literature},
year = {2008},
publisher = {Maastricht Graduate School of Governance, Maastricht University},
address = {Maastricht},
number = {Working Paper MGSoG/2008/WP002},
}