Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
ban hanh » ban hang
cham duc » pham duc, cham soc, pham duy
lang van » dang van, tang van, hoang van
duc ban » duc tan, duc van, dua ban
su dang » su dung
lang xa » lang ha, dang xay
su viet » so viet
dang y » dang xay
vi su » va su, ve su, ki su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su dang y ((lang xa) or (lang van)) hoi. ((hieu van) OR (thien van)) cham duc ban hanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su dang y ((lang xa) OR (lang van)) hoi. ((hieu van) OR (thien van)) cham duc ban hanh vi su viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su dang y ((lang xa) or (lang van)) hoi. ((hieu van) OR (thien van)) cham duc ban hanh vi su viet*".