Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, dam thuc
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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 y) or (sach tu)) nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va dan di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach y) OR (sach tu)) nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va dan di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach y) or (sach tu)) nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va dan di cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach y) or (sach tu)) nang x hoi. hieu va ((cam tuc) OR (nam thuc)) va dan di cua tre*.