Perhaps you should try some spelling variations:
sach doanh » sach danh, sach tranh, cac doanh
san nghiep » van nghiep, nang nghiep, luan nghiep
toc khach » soc khach, toc sach, tri khach
khach san » khach hang, thanh san
nghiep du » nghiep dau, nghiep tu, nghiep di
tu sach » thu sach, su sach, te sach
du hoc » tu hoc, duoc hoc

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

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