Perhaps you should try some spelling variations:
cham thuc » pham thuc, tham thuc, pham thuoc
nham thuc » nhan thuc, nam thuc, nham thu
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
su hien » su kien, su tien, thu hien
va dat » va dao, va dau, va dap

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