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
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
y lang » _ lang, tay lang, yen lang
o lang » hoa lang, hoi lang
ve cap » ve cac, le cap, ve cai
vi cuu » vi luu, vinh cuu

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