Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
vu sach » vu bach, su sach, vu khach
hieu ve » hieu va
ly hang » ly quang
di cua » dai cua, doi cua, de cua

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

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