Perhaps you should try some spelling variations:
doanh tang » doanh sang, doanh thanh, doanh quang
doanh tong » doanh trong, doanh thuong, anh tong
hoc sach » hoc sinh, hoc cac, hoc anh
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
cac tuc » cac toc, cac tac, cac nuoc
hieu ve » hieu va, hieu van
dang ha » dong ha, dung ha, lang ha
ky dang » ky nang, ky danh
cac tu » cac thu, cach tu, cac du
ha hoi » hoa hoi, ha noi, xa hoi

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

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