Looking for information about the YVANOVICH family, from Venice, Italy or Dalmatia, Yugoslavia (possibly Ragusa) (conflicting info).

Ancestor's name was Antonio YVANOVICH, est birthdate 1819, married in Macau in 1844 to Angelica de SOUSA, of Macau.

I'd greatly appreciate any information or suggestions as I'm unfamiliar with both of these areas.

Thanks, J