Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
thanh va » thanh van, hanh va, thanh ha
quoc ban » quoc bao, quoc lan, quoc quan
xuc ban » duc ban, cuc ban, xuat ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
hai hai » khai hai, dai hai, tai hai
hai hoi » dai hoi, hai moi, hai hoa
va cao » va cac, va co, va dao
va va » va van, va vua, va vai

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 nang ((hai hoi) OR (hai hai)). hieu va cao ((xuc ban) or (quoc ban)) thanh va va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((hai hoi) OR (hai hai)). hieu va cao ((xuc ban) OR (quoc ban)) thanh va va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((hai hoi) OR (hai hai)). hieu va cao ((xuc ban) or (quoc ban)) thanh va va triet*".