Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
co duc » co duoc, cao duc, do duc
va dan » ca dan, va dau, va dap
va dao » ca dao
te cua » tue cua, le cua, de cua
va co » vo co

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