Perhaps you should try some spelling variations:
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
ban hang » ngan hang
pham duy » pham duc
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
mai hoi » mai khoi, dai hoi, lai hoi
duy ban » uy ban, duy van, duy can
hang vi » hang va, hanh vi, hang di
san ky » sang ky, van ky, dan ky
me hoi » le hoi
tu san » thu san, tu ban, tu can

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky nang ((me hoi) or (mai hoi)). hieu van pham duy ban hang vi ((cua triet) OR (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky nang ((me hoi) OR (mai hoi)). hieu van pham duy ban hang vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu san ky nang ((me hoi) or (mai hoi)). hieu van pham duy ban hang vi ((cua triet) OR (cua viet))".
• Adding a wildcard symbol may retrieve word variants: tu san ky nang ((me hoi) or (mai hoi)). hieu van pham duy ban hang vi ((cua triet) OR (cua viet))*.