Perhaps you should try some spelling variations:
trung van » truong van, trong van, trung va
va triet » va thiet, va trien, ve triet
van dinh » van minh, van dich, va dinh
dang xay » dang van, van xay
dinh ve » dinh ket, dinh van
hieu va » lieu va, hieu qua
so sach » so sanh, bo sach, co sach
sang ma » tang ma, nang ma, sang tao
va tai » va tac, va tap
ve va » ve van, te va, ke va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((((nang x) or (dang xay))) or (sang ma)) hoi. hieu va tai trung van dinh ve va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((((nang x) OR (dang xay))) OR (sang ma)) hoi. hieu va tai trung van dinh ve va triet.
• Adding a wildcard symbol may retrieve word variants: so sach y ((((nang x) or (dang xay))) or (sang ma)) hoi. hieu va tai trung van dinh ve va triet*.