Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thuc ban » thuoc ban, thuc dan, thu ban
hieu van » hieu va, thien van, lieu va
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
so sach » so sanh, bo sach, co sach
vai cua » dai cua, hai cua, lai cua
su sach » vu sach
van am » van nam, van lam, van dam
vi 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 tang xa hoi. hieu van am thuc ban thanh ((vi cua) OR (vai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky tang xa hoi. hieu van am thuc ban thanh ((vi cua) OR (vai cua)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky tang xa hoi. hieu van am thuc ban thanh ((vi cua) OR (vai cua)) viet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ky tang xa hoi. hieu van am thuc ban thanh ((vi cua) OR (vai cua)) viet*.