Perhaps you should try some spelling variations:
va doanh » van doanh, vay doanh, va danh
sach ky » sac ky, sach ty, sach kem
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
nam tuc » nam thuc, nam truc, nam tu
va nam » van nam, ha nam, va nay
tuc va » thuc va, truc va, tuc xa
cua te » cua tu
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ky) or (sach y)) nang xa hoi. hieu va nam tuc va doanh tai ((cua te) or (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sach y)) nang xa hoi. hieu va nam tuc va doanh tai ((cua te) OR (cua su)).
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) or (sach y)) nang xa hoi. hieu va nam tuc va doanh tai ((cua te) or (cua su))*.