Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
cau treo » cau tren, cau triet, cau trieu
ban hang » ngan hang
thuc ban » thuoc ban, thuc dan, thu ban
coc thuc » hoc thuc, doc thuc, co thuc
hang vi » hang va, hanh vi, hang di
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
ve coc » ve cuoc, ve cac, ve co
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 v nang ((x hoi) OR (o hoi)). hieu ve coc thuc ban hang vi ((cau treo) or (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang ((x hoi) OR (o hoi)). hieu ve coc thuc ban hang vi ((cau treo) OR (cau theo)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang ((x hoi) OR (o hoi)). hieu ve coc thuc ban hang vi ((cau treo) or (cau theo))".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ((x hoi) OR (o hoi)). hieu ve coc thuc ban hang vi ((cau treo) or (cau theo))*.