Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
cau tren » cu tren, dau tren, ca tren
toan cau » toan cao, toan ban, toan tap
quoc ban » quoc bao, quoc lan, quoc quan
xuc ban » duc ban, cuc ban, xuat ban
te sach » toc sach
dai hoi » dai hoc, dai hai
dai moi » doi moi
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao
y nang » ky nang, ly nang, v nang

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

• 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 ((xuc ban) OR (quoc ban)) thanh toan 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 ((xuc ban) OR (quoc ban)) thanh toan cau tren~".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((dai hoi) or (dai moi)). hieu va cam ((xuc ban) OR (quoc ban)) thanh toan cau tren*.