Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cham tu » pham tu, cam tu, chai tu
cua tre » cua te, cuu tre, cua triet
tu van » tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky ((nang xa) OR (lang xa)) hoi. hieu ve cham tu van hanh vi ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((nang xa) OR (lang xa)) hoi. hieu ve cham tu van hanh vi ((cua tre) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky ((nang xa) OR (lang xa)) hoi. hieu ve cham tu van hanh vi ((cua tre) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((nang xa) OR (lang xa)) hoi. hieu ve cham tu van hanh vi ((cua tre) or (va triet))*.