Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
toc sach » hoc sach, doc sach, thuoc sach
toan cua » than cua, tan cua, doanh cua
hieu van » hieu va, thien van, lieu va
hieu ve » hieu va
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
luc va » tuc va, loc va
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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 nang ma hoi. ((hieu ve) OR (hieu van)) cam ((luc va) or (duc va)) thanh toan cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ma hoi. ((hieu ve) OR (hieu van)) cam ((luc va) OR (duc va)) thanh toan cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang ma hoi. ((hieu ve) OR (hieu van)) cam ((luc va) or (duc va)) thanh toan cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ma hoi. ((hieu ve) OR (hieu van)) cam ((luc va) or (duc va)) thanh toan cua te*.