Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
cam truc » cau truc, nam truc, lam truoc
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
su triet » su viet, su tien, ve triet
te sach » toc sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
y lang » o lang, _ lang, tay lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y lang xa hoi. ((hieu van) or (hieu va)) cam truc ((van hanh) OR (ban hanh)) va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y lang xa hoi. ((hieu van) OR (hieu va)) cam truc ((van hanh) OR (ban hanh)) va su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y lang xa hoi. ((hieu van) or (hieu va)) cam truc ((van hanh) OR (ban hanh)) va su triet".
• Adding a wildcard symbol may retrieve word variants: te sach y lang xa hoi. ((hieu van) or (hieu va)) cam truc ((van hanh) OR (ban hanh)) va su triet*.