Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thuc day » thuc dan, thuc vat
thuc va » thuc vat, thuc dan
su sach » vu sach
hieu ve » hieu va, hieu van
so sach » so sanh, bo sach, co sach
vi cua » vai cua, di cua
ve nam » he nam, va nam, le nam
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: ((su sach) or (so sach)) ky nang x hoi. hieu ve nam ((thuc va) OR (thuc day)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky nang x hoi. hieu ve nam ((thuc va) OR (thuc day)) hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang x hoi. hieu ve nam ((thuc va) OR (thuc day)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ky nang x hoi. hieu ve nam ((thuc va) OR (thuc day)) hanh vi cua viet*.