Perhaps you should try some spelling variations:
doanh van » doan van, doanh ban, doanh nhan
hieu quan » hieu qua, lieu quan, thien quan
doanh va » doan va, doanh tai, doanh cua
quan cau » quang cao, toan cau, quan ha
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cau duc » cao duc, cau luc, chu duc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
vi cua » vai cua, di 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 ky ((((doanh van) OR (doanh va))) or (dinh van)) hoi. hieu quan cau duc va danh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((((doanh van) OR (doanh va))) OR (dinh van)) hoi. hieu quan cau duc va danh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((((doanh van) OR (doanh va))) or (dinh van)) hoi. hieu quan cau duc va danh vi cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((((doanh van) OR (doanh va))) or (dinh van)) hoi. hieu quan cau duc va danh vi cua te*.