Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach ty, sach kem
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
van dai » vanh dai, van dao, van hai
cuu tre » cua tre, cau treo
luc va » duc va, tuc va, loc va
x hoi » xa hoi, o hoi, x ho

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

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