Perhaps you should try some spelling variations:
thien van » thi van
cua triet » cua viet, su triet, va triet
hieu van » hieu va, lieu va, hieu ve
duc manh » suc manh, duc anh, duc minh
so sach » so sanh, bo sach, co sach
duc van » duc va, duc tan, duc phan
y nang » ky nang, ly nang, v nang
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: so sach y nang o hoi. ((hieu van) OR (thien van)) chat ((duc van) or (duc manh)) hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y nang o hoi. ((hieu van) OR (thien van)) chat ((duc van) OR (duc manh)) hanh vi cua triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang o hoi. ((hieu van) OR (thien van)) chat ((duc van) or (duc manh)) hanh vi cua triet*".