Perhaps you should try some spelling variations:
doanh van » doanh va, doanh ban, doanh nhan
doan van » doan va, hoang van, luan van
danh vai » danh sai, danh va, dang van
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
cac cua » cach cua, cac qua, ca cua
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
ma hoi » mai hoi, xa hoi, ma hoa

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 tang ma hoi. hieu ve cac cua ban ((danh vai) or (((doanh van) or (doan van)))) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ma hoi. hieu ve cac cua ban ((danh vai) OR (((doanh van) OR (doan van)))) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang ma hoi. hieu ve cac cua ban ((danh vai) or (((doanh van) or (doan van)))) cua tre*.