Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
cao suc » cao su, cao duc
va hanh » van hanh, va thanh, va danh
lua tre » cua tre, luy tre, dua tren
va cao » va cac, va co, va dao
suc va » duc va, tuc va, luc va
vi lua » vi luu

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 ky ((mang xa) or (nang x)) hoi. hieu va cao suc va hanh vi lua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((mang xa) OR (nang x)) hoi. hieu va cao suc va hanh vi lua tre*.