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
qua cac » cua cac
cac duc » cac du, cao duc, cac dac
cua cua » cua chua, ca cua, qua cua
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: ((tu sach) OR (thu sach)) ky ((nang x) or (nang cao)) hoi. hieu qua cac duc va doanh cua cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky ((nang x) OR (nang cao)) hoi. hieu qua cac duc va doanh cua cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky ((nang x) or (nang cao)) hoi. hieu qua cac duc va doanh cua cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky ((nang x) or (nang cao)) hoi. hieu qua cac duc va doanh cua cua te*.