Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ban so » ban do, ban co, ban bo
so van » su van, vo van

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 ho. hieu van ban so van hanh vi ((cua triet) OR (va triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x ho. hieu van ban so van hanh vi ((cua triet) OR (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu van ban so van hanh vi ((cua triet) OR (va triet))*.