Perhaps you should try some spelling variations:
dung doi » huong doi, dung tai, dung co
vat dung » van dung, va dung, viet dung
hieu van » thien van, lieu va, hieu ve
sach ky » sac ky, sach ty, sach kem
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
cam tu » cam thu, nam tu, dam tu
tu vat » tu va, tu van, tu bat
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: su ((sach ky) OR (sach y)) nang x hoi. ((hieu va) OR (hieu van)) cam tu vat dung doi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) nang x hoi. ((hieu va) or (hieu van)) cam tu vat dung doi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach y)) nang x hoi. ((hieu va) or (hieu van)) cam tu vat dung doi cua tre*.