Perhaps you should try some spelling variations:
doanh luan » doanh nhan
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
qua cac » cua cac
cac tru » ca tru, cac tro, cac thu
y nang » ky nang, ly nang, v nang
me hoi » le hoi
tru va » truc va, tu va, trung va

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 qua cac tru va ((doanh cua) OR (doanh luan)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((me hoi) OR (ma hoa)). hieu qua cac tru va ((doanh cua) OR (doanh luan)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((me hoi) or (ma hoa)). hieu qua cac tru va ((doanh cua) OR (doanh luan)) cua triet".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((me hoi) or (ma hoa)). hieu qua cac tru va ((doanh cua) OR (doanh luan)) cua triet*.