Perhaps you should try some spelling variations:
doanh cua » doanh luan
khoa tre » khoe tre, khoa tri, khoa dr
va doanh » van doanh, vay doanh, va danh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cac tac » cac toc, cac bac, cac dac
cuu tre » cua tre, cau tren, cau treo
sach v » sach va, sach y, sach 2
tac va » tac da, tac xa, tuc va
me hoi » le hoi
v nang » va nang, vu nang, van nang

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 v nang ((me hoi) or (ma hoa)). hieu va cac tac va doanh cua ((khoa tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang ((me hoi) OR (ma hoa)). hieu va cac tac va doanh cua ((khoa tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ((me hoi) or (ma hoa)). hieu va cac tac va doanh cua ((khoa tre) or (cuu tre))*.