Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
va thanh » gia thanh, ban thanh, va tinh
cao duc » dao duc, cao suc, giao duc
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
di cau » diem cau
da cau » dat cau, va cau
ve cao » va cao, ve bao, ve cac
x hoi » xa hoi, o hoi, x ho

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

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