id	domain	url
gpej-117	dl.acm.org	http://dl.acm.org/citation.cfm?id=1600053.1600074
gpej-117	dl.acm.org	http://dl.acm.org/citation.cfm?id=1599773.1599788
gpej-117	doi.org	https://doi.org/10.1007/s11251-006-9008-z
gpej-117	doi.org	https://doi.org/10.1016/j.compedu.2009.02.010
gpej-117	doi.org	https://doi.org/10.1007/978-981-10-1972-2_3