which river's source place is postăvarul massif and mouth in valea cheii river ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_sourcePlace dbr_Postăvarul_Massif sep_dot var_uri dbo_riverMouth dbr_Valea_Cheii_River_ attr_open Ghimbășel attr_close sep_dot var_uri a dbo_River brack_close