Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
van thanh » ban thanh, van tuan
toan cua » than cua, tan cua, doanh cua
sach thu » sach thue, sach thieu, sach tham
nang dau » hang dau, xang dau, nang du
cham duc » pham duc, cham soc, pham duy
ve cham » va cham, ve chat, vu cham
duc van » duc va, duc tan, duc manh
dau hoi » cau hoi, dai hoi, dan hoi
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, xach tay
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (((sach ty) OR (sach thu)))) nang dau hoi. hieu ve cham duc van thanh toan cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (((sach ty) OR (sach thu)))) nang dau hoi. hieu ve cham duc van thanh toan cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (((sach ty) OR (sach thu)))) nang dau hoi. hieu ve cham duc van thanh toan cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (((sach ty) OR (sach thu)))) nang dau hoi. hieu ve cham duc van thanh toan cua tre*.