Perhaps you should try some spelling variations:
quoc quan » qua quan, luc quan, hoc quan
cua triet » cua viet, su triet, va triet
quoc ban » quoc bao, quoc lan, quoc binh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
hanh va » hang va, hanh vi
ve tao » ve bao, de tao, ve tac
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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