Mino, confirmation of a Southern Slav origin, and an Italian version (jurescia) here -
http://www.mundimitar.it/resetar05.it.htm
and a linking of the name with Jure in this Croatian text -
"imena u hrvatski antroponimijski sustav. Imena Ðuro (Giuro) i Ðurko (Giurko) zabilježena su, uz imena Jure i Jureška (Jurescia) ..."
which can be found here -
http://www.rb-donjahercegovina.ba/Default.aspx?id=2353