Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
va triet » va trien, ve triet, cua triet
su sach » so sach, vu sach
co sach » bo sach, cuon sach, hoc sach
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh ve » hanh vi, hanh va, hanh kem
thiet » thieu

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

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