@ARTICLE{Frątczak_Ewa_Zofia_The_2016,
 author={Frątczak, Ewa Zofia},
 number={No 23},
 howpublished={online},
 year={2016},
 publisher={Polish Academy of Sciences},
 title={The Demographic Crisis and Global Migration – Selected Issues},
 URL={http://journals.pan.pl/Content/100313/PDF/8+THE+DEMOGRAPHIC+CRISIS.pdf},
 doi={10.1515/igbp-2016-0006},
}