Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
cham thuc » pham thuc, tham thuc, pham thuoc
sach ky » sac ky, sach y, sach ty
te sach » toc sach
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
su hien » su kien, su tien, thu hien
dat vi » dat va, dat ve, dat vo
hat vi » phat vi

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 ky nang xa hoi. hieu ve ((cham thuc) or (nham thuc)) va ((dat vi) OR (hat vi)) su hien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang xa hoi. hieu ve ((cham thuc) OR (nham thuc)) va ((dat vi) OR (hat vi)) su hien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang xa hoi. hieu ve ((cham thuc) or (nham thuc)) va ((dat vi) OR (hat vi)) su hien".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang xa hoi. hieu ve ((cham thuc) or (nham thuc)) va ((dat vi) OR (hat vi)) su hien*.