Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thanh de » hanh de, thanh ve, thanh do
te sach » toc sach
sach ky » sac ky, sach y, sach ty
luc van » luoc van, luu van, luc va
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, dua tren
nang o » nang co, nang ho, nang ro
va cao » va cac, va co, va dao
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: te sach ky nang o hoi. lieu va cao ((luc van) OR (duc van)) thanh de ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang o hoi. lieu va cao ((luc van) OR (duc van)) thanh de ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang o hoi. lieu va cao ((luc van) OR (duc van)) thanh de ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang o hoi. lieu va cao ((luc van) OR (duc van)) thanh de ((cua tre) or (cua triet))*.