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, tu cach
cua cua » cua chua, ca cua, qua cua
va chat » van chat, va phat, hoa chat
nang ma » tang ma, sang ma, nang cao
te sach » toc sach
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
y nang » ky nang, ly nang, v 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) or (te sach)) y nang ma hoa. hieu ((va chat) OR (cao chat)) xuc va doanh cua cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang ma hoa. hieu ((va chat) OR (cao chat)) xuc va doanh cua cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) y nang ma hoa. hieu ((va chat) OR (cao chat)) xuc va doanh cua cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) y nang ma hoa. hieu ((va chat) OR (cao chat)) xuc va doanh cua cua tre*.