Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
nam truc » nam truoc, nam thuc, nam trung
cam truc » cau truc, lam truoc, nam truoc
sach va » sach xa, sach ha, sach dao
va hanh » van hanh, va thanh, va danh
bo sach » co sach, hoc sach
hieu ve » hieu va, hieu van
va nang » van nang, da nang, cam nang
ma hoi » mai hoi, ma hoa, me hoi
dai va » mai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach va nang ((ma hoi) OR (xa hoi)). hieu ve ((cam truc) or (nam truc)) va hanh dai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach va nang ((ma hoi) OR (xa hoi)). hieu ve ((cam truc) OR (nam truc)) va hanh dai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach va nang ((ma hoi) OR (xa hoi)). hieu ve ((cam truc) or (nam truc)) va hanh dai va triet".
• Adding a wildcard symbol may retrieve word variants: bo sach va nang ((ma hoi) OR (xa hoi)). hieu ve ((cam truc) or (nam truc)) va hanh dai va triet*.