Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nam thuc, nham thu
cham thuc » pham thuc, tham thuc, pham thuoc
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
su hien » su tien, thu hien, nhu hien
va dat » va dao, va dau, va dap
dat ki » dat vi, dat xi
kien » bien, vien, tien

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 ki ((su hien) OR (su kien))~.
• 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 ki ((su hien) OR (su kien)).
• 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 ki ((su hien) OR (su kien))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang xa hoi. hieu ve ((cham thuc) or (nham thuc)) va dat ki ((su hien) OR (su kien))*.