Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
dang van » hoang van, hang va
dan van » doan van, dao van, tan van
cao duc » dao duc, cao suc, giao duc
sach tu » sach thu, cach tu, sach ty
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, mang may
hieu va » lieu va, hieu qua
va cao » va cac, va co, va dao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu ((nang ma) OR (nang cao)) hoi. hieu va cao duc va ((dan van) OR (dang van)) su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu ((nang ma) OR (nang cao)) hoi. hieu va cao duc va ((dan van) or (dang van)) su triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach tu ((nang ma) OR (nang cao)) hoi. hieu va cao duc va ((dan van) or (dang van)) su triet*.