Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thanh lai » thanh hai, thanh lap, thanh loi
van thanh » ban thanh, van tuan
hieu voi » hieu moi, lieu voi, nhien voi
hieu loi » hieu moi, hien loi, hieu luc
co sach » bo sach, cuon sach, hoc sach
lai cua » dai cua, hai cua, lai chau
duc van » duc va, duc tan, duc manh
cua te » cua tu
nang o » nang co, nang ho, nang ro
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: ((thuat sach) or (co sach)) ky nang o hoi. ((hieu voi) OR (hieu loi)) pham duc van thanh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuat sach) OR (co sach)) ky nang o hoi. ((hieu voi) OR (hieu loi)) pham duc van thanh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuat sach) or (co sach)) ky nang o hoi. ((hieu voi) OR (hieu loi)) pham duc van thanh lai cua te".
• Adding a wildcard symbol may retrieve word variants: ((thuat sach) or (co sach)) ky nang o hoi. ((hieu voi) OR (hieu loi)) pham duc van thanh lai cua te*.