which river's source mountain is oberon and it's mouth is barwon river ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_sourceMountain dbr_Oberon,_New_South_Wales sep_dot var_uri dbo_riverMouth dbr_Barwon_River_ attr_open New_South_Wales attr_close sep_dot var_uri a dbo_River brack_close