Perhaps you should try some spelling variations:
tan doanh » toan doanh, van doanh, san doanh
hieu ve » hieu va, hieu van
tai cua » thai cua, tai cuc, tri cua
sach tu » sach thu, cach tu, sach ty
dau hoi » cau hoi, dai hoi, dau noi
cam duc » cam xuc, cao duc, pham duc
dan hoi » dan hoc, dai hoi, van hoi
cua te » cua tu
ve cam » ve cham, ve cac, va cam

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 y) or (sach tu)) nang ((dau hoi) or (dan hoi)). hieu ve cam duc tan doanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach y) OR (sach tu)) nang ((dau hoi) OR (dan hoi)). hieu ve cam duc tan doanh tai cua te.
• Adding a wildcard symbol may retrieve word variants: su ((sach y) or (sach tu)) nang ((dau hoi) or (dan hoi)). hieu ve cam duc tan doanh tai cua te*.