Perhaps you should try some spelling variations:
ban hanh » ban hang
vu sach » vu bach, su sach, vu khach
cam cac » ca cac, nam cac, cam chan
co sach » bo sach, cuon sach, hoc sach
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu van
hieu va » lieu va, hieu qua
cac ban » cac dan, cac van, can ban
vi cua » vai cua, di cua
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (co sach)) ky tang xa hoi. ((hieu ve) or (hieu va)) cam cac ban hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (co sach)) ky tang xa hoi. ((hieu ve) OR (hieu va)) cam cac ban hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (co sach)) ky tang xa hoi. ((hieu ve) or (hieu va)) cam cac ban hanh vi cua te*.