Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh dai » hanh tai, hanh dao, vanh dai
nam truc » nam truoc, nam thuc, nam trung
va hanh » van hanh, va thanh, va danh
sach va » sach ha, sach dao, sach nha
lang xa » lang ha, dang xay, lang van
sach xa » sach dao, sach nha, sach bai
hieu va » lieu va, hieu qua

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 va) OR (sach xa)) lang xa hoi. hieu va ((cau truc) or (nam truc)) va hanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach va) OR (sach xa)) lang xa hoi. hieu va ((cau truc) OR (nam truc)) va hanh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach va) OR (sach xa)) lang xa hoi. hieu va ((cau truc) or (nam truc)) va hanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach va) OR (sach xa)) lang xa hoi. hieu va ((cau truc) or (nam truc)) va hanh dai cua triet*.