Perhaps you should try some spelling variations:
hang vai » hang va, hang tai, hang hai
ban hang » ngan hang
tu sach » thu sach, su sach, te sach
vai cuu » vai cua
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
vu sach » vu bach, su sach, vu khach
ve cac » va cac, vien cac
o hoi » co hoi, o hoc, o hoa
o hai » co hai, so hai, o lai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (vu sach)) ky nang ((o hoi) or (o hai)). hieu ve cac duc ban hang vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu sach)) ky nang ((o hoi) OR (o hai)). hieu ve cac duc ban hang vai cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu sach)) ky nang ((o hoi) or (o hai)). hieu ve cac duc ban hang vai cuu tre*.