Perhaps you should try some spelling variations:
dua tren » dung tren
lam quoc » lam duoc, nam quoc, lam thuoc
thu sach » thuat sach, thuoc sach, thu hoach
ban hanh » ban hang
quoc ban » quoc bao, quoc lan, quoc quan
cua tre » cua te, cuu tre, cua triet
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang
va lam » van lam, va lap
x hoi » xa hoi, o hoi, x ho

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 (thu sach)) y nang x hoi. hieu va lam quoc ban hanh vi ((cua tre) or (dua tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y nang x hoi. hieu va lam quoc ban hanh vi ((cua tre) OR (dua tren)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) y nang x hoi. hieu va lam quoc ban hanh vi ((cua tre) or (dua tren))*.