Perhaps you should try some spelling variations:
doanh cua » doanh luan
va doanh » van doanh, vay doanh, va danh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » hieu qua
cac dac » cac dan, cac dai, cac bac
cua cua » cua chua, ca cua, qua cua
dac va » duc va, day va, dat va
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang x) or (nang cao)) hoi. ((hieu va) OR (lieu va)) cac dac va doanh cua cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang x) OR (nang cao)) hoi. ((hieu va) OR (lieu va)) cac dac va doanh cua cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang x) or (nang cao)) hoi. ((hieu va) OR (lieu va)) cac dac va doanh cua cua te*".