Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ban thanh » ban hanh, ban hang
nam thuc » nam thuoc, am thuc, nam thu
va thanh » gia thanh, va tinh, le thanh
thu sach » tu sach, thuat sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
di cua » dai cua, doi cua, de 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: thu sach y nang o hoi. ((hieu van) or (hieu va)) nam thuc ((va thanh) OR (ban thanh)) di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang o hoi. ((hieu van) OR (hieu va)) nam thuc ((va thanh) OR (ban thanh)) di cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang o hoi. ((hieu van) or (hieu va)) nam thuc ((va thanh) OR (ban thanh)) di cua triet".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang o hoi. ((hieu van) or (hieu va)) nam thuc ((va thanh) OR (ban thanh)) di cua triet*.