Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
cac thuc » cach thuc, cac thu, can thuc
van nang » van quang, van ban, van dong
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
su sach » so sach, vu sach
v nang » va nang, vu nang, voi nang

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