Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
cham luu » cham cuu, chat lua, phap luu
sach ly » sach y, sach lo, sach ty
luu van » cuu van, luan van, luu hanh
hieu ve » hieu va, hieu van
tu sach » thu sach, su sach, te sach
hieu vu » hieu va, hieu su, dieu vu
lang xa » lang ha, dang xay, lang van
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: tu sach ly ((lang xa) or (nang x)) hoi. ((hieu vu) OR (hieu ve)) cham luu van hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly ((lang xa) OR (nang x)) hoi. ((hieu vu) OR (hieu ve)) cham luu van hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly ((lang xa) or (nang x)) hoi. ((hieu vu) OR (hieu ve)) cham luu van hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ly ((lang xa) or (nang x)) hoi. ((hieu vu) OR (hieu ve)) cham luu van hanh vi su triet*.