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

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 ((dang xay) or (nang x)) hoi. hieu va cao suc va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xay) OR (nang x)) hoi. hieu va cao suc va hanh vi luu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xay) or (nang x)) hoi. hieu va cao suc va hanh vi luu tre*.