Perhaps you should try some spelling variations:
hanh lai » hanh lam, hanh tai, thanh lap
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
luc van » luoc van, luu van, luc va
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
x hoi » xa hoi, o hoi, 5 hoi

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