Perhaps you should try some spelling variations:
sach doanh » sach danh, cac doanh, san doanh
sach tranh » canh tranh
nghiep tu » nghiep vu, nghiep vua, nghiep cua
nghien d » nghiem d, nghiem de, nghiep di
nghien o » nghiep o, nghiep so, nghiep co
so sach » so sanh, bo sach, co sach
vu sach » vu bach, su sach, vu khach
tu hoc » te hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sach doanh nghiep tu hoc ) or ( vu sach tranh ((nghien d) OR (nghien o)) hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sach doanh nghiep tu hoc ) OR ( vu sach tranh ((nghien d) OR (nghien o)) hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so sach doanh nghiep tu hoc ) or ( vu sach tranh ((nghien d) OR (nghien o)) hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( so sach doanh nghiep tu hoc ) or ( vu sach tranh ((nghien d) OR (nghien o)) hoc ))*.