Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hang cau » hang dau, hang ca, nhung cau
vat danh » va danh, van danh, luat danh
nam thuc » nam thuoc, am thuc, nam thu
hieu van » thien van, lieu va, hieu ve
ly hang » ly quang
hieu va » lieu va, hieu qua
so sach » so sanh, bo sach, co sach
danh vi » hanh vi, dinh vi, danh di
su sach » vu 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 (so sach)) ly hang cau hoi. ((hieu van) or (hieu va)) nam thuc vat danh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ly hang cau hoi. ((hieu van) OR (hieu va)) nam thuc vat danh vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ly hang cau hoi. ((hieu van) or (hieu va)) nam thuc vat danh vi cua triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) ly hang cau hoi. ((hieu van) or (hieu va)) nam thuc vat danh vi cua triet*.