Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thi nang » thi cong, thi hanh
danh sai » dung sai, danh bat, danh dau
danh vai » danh va, doanh van, dang van
cao duc » dao duc, cao suc, giao duc
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
ki nang » ky nang
hieu va » lieu va, hieu qua
va cao » va cac, va co, va dao

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