Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
nam thuc » nam thuoc, am thuc, nam thu
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
va dat » va dao, va dau, va dap
vi su » va su, ki su, oi su
ve su » va su

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 (nam thuc)) va dat ((vi su) or (ve su)) tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang xa hoi. hieu ve ((cham thuc) OR (nam thuc)) va dat ((vi su) OR (ve su)) tien.
• Adding a wildcard symbol may retrieve word variants: te sach ky nang xa hoi. hieu ve ((cham thuc) or (nam thuc)) va dat ((vi su) or (ve su)) tien*.