Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
thanh di » thanh doi, thanh de, thanh do
thuc ban » thuoc ban, thuc dan, thu ban
dam thuc » am thuc, dan thuc, nam thuc
van dam » van nam, van dao, van dau
ky tang » ky dang, kho tang, ky trong
so sach » so sanh, bo sach, co sach
su sach » vu sach
di cua » dai cua, doi cua, de 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 tang) or (ky nang)) xa hoi. hieu van dam thuc ban thanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ((ky tang) OR (ky nang)) xa hoi. hieu van dam thuc ban thanh di cua viet.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ((ky tang) or (ky nang)) xa hoi. hieu van dam thuc ban thanh di cua viet*.