Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
van hanh » van thanh, ban hanh, van anh
hieu van » thien van, lieu va, hieu ve
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
bo van » vo van, so van, do van
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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