Perhaps you should try some spelling variations:
doanh tang » doanh sang, doanh tong, doanh thanh
tang cua » mang cua, hang cua, tang luan
va doanh » van doanh, vay doanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky
ha hoi » hoa hoi, ha noi, va hoi
ve cac » va cac, vien cac
toc va » hoc va, toc ta, tuc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sac ky) or (sai ky)) dang ((ha hoi) OR (xa hoi)). hieu ve cac toc va doanh tang cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sac ky) OR (sai ky)) dang ((ha hoi) OR (xa hoi)). hieu ve cac toc va doanh tang cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sac ky) or (sai ky)) dang ((ha hoi) OR (xa hoi)). hieu ve cac toc va doanh tang cua tre*".