Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
qua cham » qua hai, qua cac, va cham
duc manh » suc manh, duc anh, duc minh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc phan
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 ky nang o hoi. hieu qua cham ((duc van) or (duc manh)) hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang o hoi. hieu qua cham ((duc van) OR (duc manh)) hanh vi cua triet.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hoi. hieu qua cham ((duc van) or (duc manh)) hanh vi cua triet*.