Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
dang van » hoang van, hang va
thuc van » thuc vat, thuc dan, thuc va
cam thuc » am thuc, nam thuc, cam thu
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va
vi cua » vai cua, di cua
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky

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

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