Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
thuc day » thuc dan, thuc vat
hanh vai » hanh va, hanh tai, hanh van
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
su xac » pu xac, su cac
xac ky » cac ky, sac ky, bac ky
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su xac ky lang xa hoi. hieu ve cam thuc day ((hanh vai) or (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su xac ky lang xa hoi. hieu ve cam thuc day ((hanh vai) OR (hanh vi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: su xac ky lang xa hoi. hieu ve cam thuc day ((hanh vai) or (hanh vi)) cua tre*.