Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
than luc » nhan luc, than duc, thanh luu
va than » va thanh, van than, va phan
lai cua » dai cua, hai cua, thai cua
luc van » luoc van, luu van, duc van
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
sac ky » cac ky, sai ky
ma hoi » xa hoi, ma hoa, me hoi
tu sac » tu sach, tu cac, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang ((ma hoi) or (mai hoi)). hieu va than luc van hanh ((lai cua) OR (lai chau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((ma hoi) OR (mai hoi)). hieu va than luc van hanh ((lai cua) OR (lai chau)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((ma hoi) or (mai hoi)). hieu va than luc van hanh ((lai cua) OR (lai chau)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((ma hoi) or (mai hoi)). hieu va than luc van hanh ((lai cua) OR (lai chau)) tre*.