Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
hang cau » hang dau, hang ca, nhung cau
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
hanh de » hanh ve, hanh kem
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
sach ly » sach y, sach lo, sach hay
sach ty » sach y, sach tu, sach thu
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sach ly) OR (sach ty)) hang cau hoi. ((hieu van) or (hieu va)) nam thuc va hanh de cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ly) OR (sach ty)) hang cau hoi. ((hieu van) OR (hieu va)) nam thuc va hanh de cua triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ly) OR (sach ty)) hang cau hoi. ((hieu van) or (hieu va)) nam thuc va hanh de cua triet*".