gravesearch Vienna: http://www.friedhoefewien.at/eportal/
you find A Nikolaus Vukelic buried in Vienna but maybe his father or grandfather when you look on birthdates and burialdates. no Amalia to find so not sure if they stayed forever in Vienna:
http://www.friedhoefewien.at/grabsuche_de?submit=true&na...
Vorname/firstname: Nikolaus
Nachname/lasdtname: Vukelic
Lebensalter/age at death: 61
Bestattungsdatum/burialdate: 26.05.1908
Friedhof/cemetery: Wiener Zentralfriedhof/Vienna Central
Gruppe/group: 63
Reihe/row: 2
Nummer/number: 6
Grabnutzungsrecht bis/right for grave: auf Friedhofsdauer/ how long the cemetery exist

in same grave are buried:
Name/name Geburtsdatum/birthdate Lebensalter/age
Bauer Ingrid Hedwig Maria 01.07.1940 69
Vukelic Lazar 58
Vukelic Maria 07.04.1907 82
Vukelic Milan 82

maybe you get more details at cemetery administration Vienna > Friedhöfe Wien GmbH:
http://www.wien-konkret.at/soziales/friedhof/

Tracing your Ancestors in Vienna - Some Guidelines
A service of the Municipal and Provincial Archives of Vienna
http://www.wien.gv.at/english/history/archives/ancestors.htm...

yes Zupancic is a slovenian name and came about occupation > administrator, community leader.
Vukelic think is more of croatian orgin. phonebook Croatia has MANY hits for that name, more then 1000!

in Graz you can ask at diocesan-archive to the ancestors - you have some dates:
http://www.katholische-kirche-steiermark.at/dioezese/ordinar...
http://boards.ancestry.com/localities.ceeurope.austria.Prov....