Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
va am » va lam, va cam

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 ty nang ((x ho) or (xa hoi)). hieu va am thuc ((va danh) or (va hanh)) mai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x ho) OR (xa hoi)). hieu va am thuc ((va danh) OR (va hanh)) mai va triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x ho) or (xa hoi)). hieu va am thuc ((va danh) or (va hanh)) mai va triet*.