Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
hieu van » hieu va, thien van, hieu ve
va thanh » gia thanh, ban thanh, va tinh
te sach » toc sach
cac luc » cau luc, coc luc, cac nuoc
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi
luc va » duc va, tuc va, loc va
o hoi » o hoc, o hai, o hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thi nang ((o hoi) OR (co hoi)). ((hieu van) or (lieu va)) cac luc va thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi nang ((o hoi) OR (co hoi)). ((hieu van) OR (lieu va)) cac luc va thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi nang ((o hoi) OR (co hoi)). ((hieu van) or (lieu va)) cac luc va thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach thi nang ((o hoi) OR (co hoi)). ((hieu van) or (lieu va)) cac luc va thanh dai cua tre*.