Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
toc sach » hoc sach, doc sach, thuoc sach
dang mat » dang vat, dang mau, dung mat
toan ca » toan cao, toan cau, toan cua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
dang ma » dang mau, dang mam, tang ma
ca tren » cau tren, cu tren, la tren
ve cam » ve cham, ve cac, va cam
luc va » tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky ((dang ma) or (dang mat)) hoi. hieu ve cam ((luc va) or (duc va)) thanh toan ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((dang ma) OR (dang mat)) hoi. hieu ve cam ((luc va) OR (duc va)) thanh toan ca tren.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((dang ma) or (dang mat)) hoi. hieu ve cam ((luc va) or (duc va)) thanh toan ca tren*.