Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su sach » vu sach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
so sach » so sanh, bo sach, co sach
hieu ve » hieu va
vi cua » vai cua, di cua

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