Perhaps you should try some spelling variations:
sua triet » su triet, cua triet, sua tiet
hanh dai » hanh tai, hanh dao, vanh dai
nam truc » nam truoc, nam thuc, nam trung
cam truc » cau truc, lam truoc, nam truoc
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
dai sua » dai cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach 2) or (sach y)) nang x hoi. hieu ve ((cam truc) OR (nam truc)) va hanh dai sua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach 2) OR (sach y)) nang x hoi. hieu ve ((cam truc) OR (nam truc)) va hanh dai sua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach 2) or (sach y)) nang x hoi. hieu ve ((cam truc) OR (nam truc)) va hanh dai sua triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach 2) or (sach y)) nang x hoi. hieu ve ((cam truc) OR (nam truc)) va hanh dai sua triet*.