Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cau tren » cu tren, dau tren, ca tren
san cau » van cau, ban cau, can cau
duc ban » duc tan, duc van, dua ban
te sach » toc sach
dai moi » doi moi
dai hoi » dai hoc, dai hai
y nang » ky nang, ly nang, v nang
va cao » va cac, va co, va dao
va cam » va cham, va cac, va cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ((dai hoi) or (dai moi)). hieu ((va cam) OR (va cao)) duc ban thanh san cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((dai hoi) OR (dai moi)). hieu ((va cam) OR (va cao)) duc ban thanh san cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((dai hoi) or (dai moi)). hieu ((va cam) OR (va cao)) duc ban thanh san cau tren".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((dai hoi) or (dai moi)). hieu ((va cam) OR (va cao)) duc ban thanh san cau tren*.