http://www.concentra.com/-/media/base-themes/corelibs/scripts/fullcalendargcal.js
http://mcb.rs/wp-content/themes/openstrap/js/gcal.js?ver=4.2.2
https://www.bodynbrain.com/vendors/fullcalendar/dist/gcal.js
https://www.unobridge.com/libs/fullcalendar/dist/gcal.js