Perhaps you should try some spelling variations:
doanh ban » doanh bat, doanh van, doanh nhan
cham cuu » cap cuu, chat cua
tu sach » thu sach, te sach, tu cach
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
ly nang » ky nang, ly hang, ly vang
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
cuu va » cuu van, cuu ve
x hoi » xa hoi, o hoi, x ho

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) OR (su sach)) ly nang x hoi. hieu ve cham cuu va ((dinh van) or (doanh ban)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ly nang x hoi. hieu ve cham cuu va ((dinh van) OR (doanh ban)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ly nang x hoi. hieu ve cham cuu va ((dinh van) or (doanh ban)) cua tre*".