Perhaps you should try some spelling variations:
doanh ban » doanh bat, doanh van, doanh nhan
cham luc » cham soc, nhan luc, cham cuu
doan ban » toan ban, doan van, doanh bat
tu sach » thu sach, su sach, te sach
luc van » luoc van, luu van, duc van
ve cham » va cham, ve chat, vu cham
sach lo » sach dao, sach doi, sach hoi
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet

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

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