Perhaps you should try some spelling variations:
ban hang » ngan hang
hang dai » hoang dai, hang tai, hang dau
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
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: ((tu sach) or (su sach)) ky nang xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hang dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hang dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hang dai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hang dai cua te*.