Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
vu khach » vu khanh, vu khac, vay khach
hieu van » hieu va, thien van, lieu va
nang xa » nang x, lang xa, nang ma
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
va tich » va tinh, va dich
cua tre » cua te, cuu tre, dua tren

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

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