Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua viet » ca viet, hoa viet, cua vat
truc ban » thuc ban, truc dan, truc van
thanh va » thanh van, hanh va, thanh ha
kho tang » cao tang
cua tre » cua te, cuu tre, cua triet
su sach » vu sach
tang xa » trang xa, tang ma, lang xa
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
ve cau » ke cau, va cau, ve cac

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)) kho tang xa hoi. hieu ve cau truc ban thanh va ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) kho tang xa hoi. hieu ve cau truc ban thanh va ((cua tre) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) kho tang xa hoi. hieu ve cau truc ban thanh va ((cua tre) or (cua viet))*.