Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
nang xa » nang x, nang ma, mang xa
cua tre » cuu tre, cua triet, dua tren
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cao suc » cao su, cao duc
suc van » su van, duc van, luc van
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 y ((nang xa) or (lang xa)) hoi. hieu va cao suc van hanh lai ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (lang xa)) hoi. hieu va cao suc van hanh lai ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) or (lang xa)) hoi. hieu va cao suc van hanh lai ((cua tre) OR (cua te))*".