Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
cua triet » cua viet, su triet, va triet
thi nang » thi cong, ki nang, thi hanh
nang mai » nang ma, nang tai, lang mai
danh vai » danh sai, danh va, dang van
sach thi » sach thu, sach tai, sach thieu
te sach » toc sach
mai hoi » mai khoi, dai hoi, lai hoi
va dao » ca dao
va cao » va cac, va co, va bao

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thi nang mai hoi. hieu ((va cao) OR (va dao)) duc va ((danh vai) or (doanh van)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi nang mai hoi. hieu ((va cao) OR (va dao)) duc va ((danh vai) OR (doanh van)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi nang mai hoi. hieu ((va cao) OR (va dao)) duc va ((danh vai) or (doanh van)) cua triet".
• Adding a wildcard symbol may retrieve word variants: te sach thi nang mai hoi. hieu ((va cao) OR (va dao)) duc va ((danh vai) or (doanh van)) cua triet*.