Perhaps you should try some spelling variations:
sach tru » sach truc, sach thu, sach tu
tu sach » thu sach, su sach, te sach
danh va » doanh va, hanh va, anh va
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
va cao » va cac, va co, va dao
cua te » cua tu

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 tru ((nang xa) or (nang ma)) hoi. hieu va cao duc va ((danh va) or (doan va)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tru ((nang xa) OR (nang ma)) hoi. hieu va cao duc va ((danh va) OR (doan va)) cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach tru ((nang xa) or (nang ma)) hoi. hieu va cao duc va ((danh va) or (doan va)) cua te*.