Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam tu
te sach » toc sach
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va hang » van hang, va nang, va lang
hang vi » hang va, hanh vi, hang di
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (so sach)) ky nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va hang vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (so sach)) ky nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va hang vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (so sach)) ky nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va hang vi luu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (so sach)) ky nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va hang vi luu tre*.