Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
van hanh » van thanh, van anh, van ban
dang xay » dang van, van xay
ban hanh » ban hang
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
vai cua » dai cua, hai cua, lai cua
hieu le » hieu ve, hieu he, hieu ly
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
le nam » ly nam, he nam, le na

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((nang ma) or (dang xay)) hoi. hieu le nam thuoc ((van hanh) OR (ban hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((nang ma) OR (dang xay)) hoi. hieu le nam thuoc ((van hanh) OR (ban hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((nang ma) or (dang xay)) hoi. hieu le nam thuoc ((van hanh) OR (ban hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang ma) or (dang xay)) hoi. hieu le nam thuoc ((van hanh) OR (ban hanh)) vai cua tre*.