Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
vu khach » vu khanh, vu khac, vay khach
khach ly » khanh ly, khao ly, khich le
hieu van » thien van, lieu va, hieu ve
ly nang » ky nang, ly hang, ly vang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
cac tu » cac thu, cach tu, cac du

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

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