Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
van cac » van hac, van cau, van bac
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua
o hoi » co hoi, o hai, o hoa
o hoc » co hoc, mo hoc, so hoc

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((5 hoi) OR (((o hoi) OR (o hoc)))). hieu van cac tuc va hanh vi cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang ((5 hoi) or (((o hoi) OR (o hoc)))). hieu van cac tuc va hanh vi cua triet~".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((5 hoi) or (((o hoi) OR (o hoc)))). hieu van cac tuc va hanh vi cua triet*.