Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
cam thuc » am thuc, cam thu, can thuc
hieu van » hieu va, thien van, lieu va
va nang » van nang, da nang, cam nang
cao hoi » cau hoi, co hoi, cao hoc
vu sach » vu bach, vu khach
va hanh » van hanh, va thanh, va danh
su sach » so sach
vi cua » vai cua, di cua

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