Perhaps you should try some spelling variations:
doanh cua » doanh luan
va doanh » van doanh, vay doanh, va danh
tu sach » thu sach, su sach, te sach
cua cua » cua chua, ca cua, qua cua
cac toc » cac toi, cac nuoc, cac thoi
cac tuc » cac tu, cac tac, cac nuoc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
me hoi » le hoi

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 nang ((me hoi) OR (ma hoa)). hieu va ((cac tuc) OR (cac toc)) va doanh cua cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((me hoi) OR (ma hoa)). hieu va ((cac tuc) OR (cac toc)) va doanh cua cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((me hoi) OR (ma hoa)). hieu va ((cac tuc) OR (cac toc)) va doanh cua cua tre*.