You will find some info on the Danube Schwabian (what Germans from this region are called) at the helping hands web page

http://www.dvhh.org/batschka/village/Bukin.htm

Bachbobrck probably refers to the region, called Batchka or Bačka where Bukin is located

http://en.wikipedia.org/wiki/Ba%C4%8Dka

http://en.wikipedia.org/wiki/Mladenovo

However it you look at their birthplaces it lists Bukovar, which I would take to be Vukovar, which is across the Danube River in Croatia.

You will find numerous Vukovar records online at

https://www.familysearch.org/search/collection/2040054

Robert