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

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