Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc quan, quoc binh
quoc lan » nuoc luan, quoc quan, quoc danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
via cua » gia cua, gian cua, giau cua
va cao » va cac, va co, va dao
va cua » va chua, ca cua, ma cua

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 xa hoi. hieu va cao ((quoc ban) or (quoc lan)) thanh ((va cua) OR (via cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu va cao ((quoc ban) OR (quoc lan)) thanh ((va cua) OR (via cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu va cao ((quoc ban) or (quoc lan)) thanh ((va cua) OR (via cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu va cao ((quoc ban) or (quoc lan)) thanh ((va cua) OR (via cua)) triet*.