Perhaps you should try some spelling variations:
thanh dieu » thanh lieu, than dieu, hanh dieu
tran thanh » ban thanh, van thanh, quan thanh
hieu van » hieu va, thien van, hieu ve
dieu cua » dieu tra
duc tran » duc tan, duc toan, duc tren
cac duc » cac du, cao duc, cac dac
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
nang o » nang co, nang ho, nang ro
cua te » cua tu
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: tu ((sach ty) OR (sach tu)) nang o hoi. ((hieu van) or (lieu va)) cac duc tran thanh dieu cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) nang o hoi. ((hieu van) OR (lieu va)) cac duc tran thanh dieu cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach tu)) nang o hoi. ((hieu van) or (lieu va)) cac duc tran thanh dieu cua te".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach tu)) nang o hoi. ((hieu van) or (lieu va)) cac duc tran thanh dieu cua te*.