Perhaps you should try some spelling variations:
thu san » thuy san, thu ban, phu san
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
va hang » van hang, va nang, va lang
hang di » hang doi, hang vi, hang dien
san ky » sang ky, van ky, dan ky
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

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