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

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) OR (ly nam)) thuoc van 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) OR (ly nam)) thuoc van 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) OR (ly nam)) thuoc van hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang ma) or (dang xay)) hoi. hieu ((le nam) OR (ly nam)) thuoc van hanh vai cua tre*.