Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cham dua » chay dua, cham giua, pham duc
hang hoi » hang hoa, hang hai, hang doi
ban hang » ngan hang
cuu tre » cua tre, cau treo
dua ban » dia ban, cua ban, qua ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
dai hoi » dai hoc, dai hai, dai moi
mai hoi » mai khoi, lai hoi, mai doi
ve cham » va cham, ve chat, vu cham

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 ky nang ((mai hoi) or (dai hoi)). hieu ve cham dua ban hang hoi ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((mai hoi) OR (dai hoi)). hieu ve cham dua ban hang hoi ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((mai hoi) or (dai hoi)). hieu ve cham dua ban hang hoi ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((mai hoi) or (dai hoi)). hieu ve cham dua ban hang hoi ((cuu tre) OR (cau tren))*.