Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
tuan tuc » thuan thuc, luan thuc, tuan tuoi
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
tuan tu » tuan thu, tran tu, toan tu
tu sach » thu sach, su sach, tu cach
nang xa » nang x, lang xa, nang ma
vu nang » vuc nang, va nang, vu dang
te sach » toc sach
cua tre » cua te, cuu tre, cua triet

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 (te sach)) vu nang xa hoi. hieu van ((tuan tuc) or (tuan tu)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) vu nang xa hoi. hieu van ((tuan tuc) OR (tuan tu)) va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) vu nang xa hoi. hieu van ((tuan tuc) or (tuan tu)) va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) vu nang xa hoi. hieu van ((tuan tuc) or (tuan tu)) va hanh vai cua tre*.