Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
hieu ve » hieu va, hieu van
tu sach » thu sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
su sach » so sach, vu sach
va dan » ca dan, va dao, va dau
vi su » va su, ve su, ki su
ve am » va am

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky nang xa hoi. hieu ve am thuc ((van hanh) or (va dan)) vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. hieu ve am thuc ((van hanh) OR (va dan)) vi su triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang xa hoi. hieu ve am thuc ((van hanh) or (va dan)) vi su triet*.