Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
nang xay » nganh xay, nang xuan, nang cao
toan luu » toan lua, thanh luu, toan luan
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
sach ky » sac ky, sach y, sach ty
luu tre » luu tru, cuu tre, luy tre
xuc va » tuc va, luc va, xac va

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 ky ((nang xay) or (dang xay)) hoi. hieu ve chat ((xuc va) OR (duc va)) thanh toan luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xay) OR (dang xay)) hoi. hieu ve chat ((xuc va) OR (duc va)) thanh toan luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xay) or (dang xay)) hoi. hieu ve chat ((xuc va) OR (duc va)) thanh toan luu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xay) or (dang xay)) hoi. hieu ve chat ((xuc va) OR (duc va)) thanh toan luu tre*.