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
cam truc » cau truc, lam truoc, nam truoc
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
va lang » va nang, hoa lang
v lang » o lang, _ lang, van lang

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