id	domain	url
dem-14839	www.dem.umk.pl	http://www.dem.umk.pl/dem
dem-14839	dx.doi.org	http://dx.doi.org/10.12775/dem.2017.007
dem-14839	dx.doi.org	https://dx.doi.org/10.1016/j.qref.2016.01.004
dem-14839	dx.doi.org	https://dx.doi.org
dem-14839	dx.doi.org	https://dx.doi.org
dem-14839	dx.doi.org	https://dx.doi.org
dem-14839	dx.doi.org	https://dx.doi.org