Perhaps you should try some spelling variations:
doanh ban » doanh bat, doanh nhan, doanh luan
doanh van » doan van, doanh va, doanh nhan
te sach » toc sach
cac tuc » cac toc, cac tu, cac tac
tuc vay » tuc va, tu vay, tuc xay
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
ha hoi » ha noi, xa hoi, va hoi

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

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