Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
thu sach » tu sach, thuat sach, thuoc sach
duc van » duc va, duc tan, duc manh
te sach » toc sach
ve tai » te tai, de tai, le tai
nang o » nang co, nang ho, nang ro
vi cua » vai cua, di cua
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: ((te sach) or (thu sach)) ky nang o hoi. hieu ((ve tai) or (va cac)) duc van hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (thu sach)) ky nang o hoi. hieu ((ve tai) OR (va cac)) duc van hanh vi cua triet.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (thu sach)) ky nang o hoi. hieu ((ve tai) or (va cac)) duc van hanh vi cua triet*.