Perhaps you should try some spelling variations:
doanh cua » doanh luan
thu sach » thuat sach, thuoc sach, thu hoach
va doanh » van doanh, vay doanh, va danh
tu sach » su sach, te sach, tu cach
cua cua » cua chua, ca cua, qua cua
cac tru » ca tru, cac tro, cac thu
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
me hoi » le hoi
tru va » truc va, tu va, trung 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 (thu sach)) y nang ((me hoi) or (ma hoa)). hieu va cac tru va doanh cua cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y nang ((me hoi) OR (ma hoa)). hieu va cac tru va doanh cua cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) y nang ((me hoi) or (ma hoa)). hieu va cac tru va doanh cua cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) y nang ((me hoi) or (ma hoa)). hieu va cac tru va doanh cua cua tre*.