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
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang o » nang co, nang ho, nang ro
va ban » van ban, va bai, va bao
ban bo » can bo, ban do, ban co
bo van » vo van, so van, do van
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) OR (sach ty)) nang o hoi. hieu va ban bo van hanh vi ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang o hoi. hieu va ban bo van hanh vi ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang o hoi. hieu va ban bo van hanh vi ((cua triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang o hoi. hieu va ban bo van hanh vi ((cua triet) or (su triet))*.