Perhaps you should try some spelling variations:
ban doanh » van doanh, san doanh, ban danh
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
ve cai » va cai, ve tai, ve cau
ve cac » va cac, vien cac
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y lang xa hoi. hieu ((ve cai) OR (ve cac)) cuu ((ban doanh) or (ban hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y lang xa hoi. hieu ((ve cai) OR (ve cac)) cuu ((ban doanh) OR (ban hanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y lang xa hoi. hieu ((ve cai) OR (ve cac)) cuu ((ban doanh) or (ban hanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y lang xa hoi. hieu ((ve cai) OR (ve cac)) cuu ((ban doanh) or (ban hanh)) vi cua tre*.