Perhaps you should try some spelling variations:
thanh do » thanh de, thanh pho, thanh hoa
thanh di » thanh doi, thanh de, thanh dinh
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
cao tuc » dao tuc, cao duc, cao suc
cua tre » cua te, cuu tre, cua triet
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
tuc va » thuc va, truc va, tuc xa
va cao » va cac, va co, va dao

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 ty ((mang xa) or (nang x)) hoi. hieu va cao tuc va ((thanh di) OR (thanh do)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((mang xa) OR (nang x)) hoi. hieu va cao tuc va ((thanh di) OR (thanh do)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((mang xa) or (nang x)) hoi. hieu va cao tuc va ((thanh di) OR (thanh do)) cua tre*".