Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
nang hai » hang hai, nang tai, dang hai
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
hai hoi » dai hoi, hai moi, hai hai
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. ((hieu va) OR (hieu qua)) 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. ((hieu va) OR (hieu qua)) 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. ((hieu va) OR (hieu qua)) cao ((xuc ban) or (quoc ban)) thanh va va triet*".