hello im chasing anyone with information on the surname globarevic in montenegro

My real grandfathers name was DRAGO GLOBAREVIC and he was born abt1933 in montenegro and died age 45 in 1978 in Tasmania australia

this is all i know and very very frustrating as i know he had another family after leaving my grandmother but for the life of me there isnt a trace of any globarevics in australia online ........i dont know what to do