Perhaps you should try some spelling variations:
doanh mang » doanh sang, doanh quang, doanh ban
hieu van » thien van, lieu va, hieu ve
va doanh » van doanh, vay doanh, va danh
su sach » so sach, vu sach
cua tre » cua te, cua triet, dua tren
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cuu tre » cau tren, cau treo
y nang » ky nang, ly nang, v nang
cuu va » cuu van, cuu ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang xa hoi. ((hieu va) or (hieu van)) cap cuu va doanh mang ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. ((hieu va) OR (hieu van)) cap cuu va doanh mang ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. ((hieu va) or (hieu van)) cap cuu va doanh mang ((cua tre) OR (cuu tre))*".