Perhaps you should try some spelling variations:
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
va cau » van cau, va cac, va dau
loc va » hoc va
luc va » duc va, tuc va
vi cua » vai cua, di cua

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

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