Perhaps you should try some spelling variations:
thanh toan » thanh hoa, thanh san, tinh toan
cua triet » cua viet, su triet, va triet
van thanh » ban thanh, van tuan
cham duc » pham duc, cham soc, pham duy
nang dau » hang dau, xang dau, nang du
cua tre » cua te, cuu tre, dua tren
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
dau hoi » cau hoi, dai hoi, dan hoi
sach ty » sach y, sach tu, sach thu
sac ky » cac ky, sai ky

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

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