Perhaps you should try some spelling variations:
thanh luc » thanh luu, than luc, nhan luc
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, te sach, tu cach
vai cua » dai cua, hai cua, lai cua
luc van » luoc van, luu van, duc van
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
v nang » va nang, vu nang, van nang

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

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