Perhaps you should try some spelling variations:
thanh ve » hanh ve, thanh va, thanh vien
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
suc va » duc va, luc va, soc va
tuc va » thuc va, truc va, tuc xa
ve cua » le cua, de cua, te cua

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 y ((lang xa) or (nang x)) hoi. hieu va cao ((suc va) OR (tuc va)) thanh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((lang xa) OR (nang x)) hoi. hieu va cao ((suc va) OR (tuc va)) thanh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((lang xa) or (nang x)) hoi. hieu va cao ((suc va) OR (tuc va)) thanh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((lang xa) or (nang x)) hoi. hieu va cao ((suc va) OR (tuc va)) thanh ve cua tre*.