Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
vat thanh » dat thanh, gat thanh, tat thanh
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam tu
thanh di » thanh doi, thanh de, thanh do
y nang » ky nang, ly nang, v nang
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, x ho, 5 hoi
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: hoc sach y nang ((x hoi) OR (o hoi)). hieu van ((nam thuc) or (nam thu)) vat thanh di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y nang ((x hoi) OR (o hoi)). hieu van ((nam thuc) OR (nam thu)) vat thanh di cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach y nang ((x hoi) OR (o hoi)). hieu van ((nam thuc) or (nam thu)) vat thanh di cua triet".
• Adding a wildcard symbol may retrieve word variants: hoc sach y nang ((x hoi) OR (o hoi)). hieu van ((nam thuc) or (nam thu)) vat thanh di cua triet*.