Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
cau tren » cu tren, dau tren, ca tren
dun nang » dung nang, den nang, luan nang
toan cau » toan cao, toan ban, toan tap
duy nong » duy tuong, duy thong, duy phong
va thanh » gia thanh, ban thanh, va tinh
tham duc » pham duc, tham du, than duc
va tham » van tham, va cham, va thuat
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
ma hoi » mai hoi, ma hoa, me 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 ((dun nang) or (duy nong)) ((ma hoi) OR (xa hoi)). hieu va tham duc va thanh toan cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((dun nang) OR (duy nong)) ((ma hoi) OR (xa hoi)). hieu va tham duc va thanh toan cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((dun nang) or (duy nong)) ((ma hoi) OR (xa hoi)). hieu va tham duc va thanh toan cau tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ((dun nang) or (duy nong)) ((ma hoi) OR (xa hoi)). hieu va tham duc va thanh toan cau tren*.