Ечка / Ečka / Ecica / Etschka
http://en.wikipedia.org/wiki/E%C4%8DkaAnd it looks like you have relatives who still live in the same town:
http://www.11811.rs/belestrane/detaljnije/858c463ae33698957c...(KADARIJAN surname is the same as Cadarian, only spelled in Serbian language and the way it is pronounced)
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"Rodoslovlje" Serbian Genealogy Society
www.facebook.com/rodoslovlje