Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
tu sach » su sach, te sach, tu cach
tu nang » tru nang, tu nong, tu nano
hieu vu » hieu va, hieu ve, hieu su
vu pham » su pham, vi pham, vu kham
va hanh » van hanh, va thanh, va danh
hanh de » hanh ve, hanh kem
de va » de van, te va, ke va

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 (thu sach)) tu nang x ho. hieu vu pham duc va hanh de va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu nang x ho. hieu vu pham duc va hanh de va triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tu nang x ho. hieu vu pham duc va hanh de va triet*.