Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
lam thuc » lam thuoc, am thuc, nam thuc
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
van lam » van nam
xay hoi » xa hoi, cay phoi, gay thoi
tay hoi » tay ho, tao hoi, tay thai
ly van » le van, ly va, ly von

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ly van ((xay hoi) OR (tay hoi)). hieu van lam thuc dan hanh vai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ly van ((xay hoi) OR (tay hoi)). hieu van lam thuc dan hanh vai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ly van ((xay hoi) OR (tay hoi)). hieu van lam thuc dan hanh vai cua triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ly van ((xay hoi) OR (tay hoi)). hieu van lam thuc dan hanh vai cua triet*.