Perhaps you should try some spelling variations:
dung cong » dung trong
vat dung » van dung, va dung, viet dung
cuu tre » cau tren, cau treo
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cua triet, dua tren
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
tu vat » tu va, tu van, tu bat
so sac » so sach, so dac
nam tu » nam thu, nam thuc
sac ky » cac ky, sai ky
ve nam » he nam, va nam, le nam

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: so sac ky ((nang xa) OR (nang ma)) hoi. hieu ve nam tu vat dung cong ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky ((nang xa) OR (nang ma)) hoi. hieu ve nam tu vat dung cong ((cua tre) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: so sac ky ((nang xa) OR (nang ma)) hoi. hieu ve nam tu vat dung cong ((cua tre) or (cuu tre))*.