id	domain	url
dialog-502	gradworks.umi.com	http://gradworks.umi.com/35/01/3501610.html
dialog-502	doi.org	http://doi.org/10.1080/10409280701838603
dialog-502	www.youtube.com	https://www.youtube.com/watch?v=v518byov2nq
dialog-502	gradworks.umi.com	http://gradworks.umi.com/35/01/3501610.html