Perhaps you should try some spelling variations:
dung doi » huong doi, dung tai, dung co
vat dung » van dung, va dung, viet dung
doi cuu » doi cua, doi cuoc
sach ky » sach y, sach ty, sach kem
hieu va » hieu qua
cuu tre » cua tre, cau tren, cau treo
nang o » nang co, nang ho, nang ro
cam tu » cam thu, nam tu, dam tu
tu vat » tu va, tu van, tu bat
sac ky » cac ky, sai ky
o hoi » co hoi, o hoc, o hai

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 (sac ky)) nang o hoi. ((hieu va) OR (lieu va)) cam tu vat dung doi cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang o hoi. ((hieu va) or (lieu va)) cam tu vat dung doi cuu tre~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang o hoi. ((hieu va) or (lieu va)) cam tu vat dung doi cuu tre*.