Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
thanh lam » thanh lap, hanh lam, thanh nam
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
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 ty nang o hoi. hieu van cau duc va thanh lam ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang o hoi. hieu van cau duc va thanh lam ((cua triet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang o hoi. hieu van cau duc va thanh lam ((cua triet) or (su triet))*.