id	domain	url
issue-504	doi.org	https://doi.org/10.30525/2256-0742/2018-4-4-233-237
issue-504	www.radiosvoboda.org	https://www.radiosvoboda.org/a/29359933
issue-504	it4reform.org	http://it4reform.org/2015/02/23/top-3
issue-504	academy.gov.ua	http://academy.gov.ua/ej/ej19/pdf/22.pdf
issue-504	www.viaduk.net	http://www.viaduk.net/clients/vsu/vsu.nsf/(documents)