Perhaps you should try some spelling variations:
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
hieu va » lieu va, hieu qua
hieu ve » hieu van
lang xa » lang ha, dang xay, lang van
sac ky » cac ky, sai ky
toc va » hoc va, toc ta, tuc va
vi cua » vai cua, di cua
tu sac » tu sach, tu cac, tu san

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 ((lang xa) or (nang x)) hoi. ((hieu ve) or (hieu va)) cac toc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((lang xa) OR (nang x)) hoi. ((hieu ve) OR (hieu va)) cac toc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((lang xa) or (nang x)) hoi. ((hieu ve) or (hieu va)) cac toc va hanh vi cua tre*.