Perhaps you should try some spelling variations:
cua triet » su triet, va triet
hieu van » thien van, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

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