Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
dac san » dac sac, cac san, dac nhan
cua tre » cuu tre, cua triet, dua tren
dac ban » cac ban, duc ban, da ban
van bac » van ban, van bao, van hac
y nang » ky nang, ly nang, v nang
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 y nang o hoi. hieu van bac ((dac ban) OR (dac san)) hanh dai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hoi. hieu van bac ((dac ban) OR (dac san)) hanh dai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hoi. hieu van bac ((dac ban) OR (dac san)) hanh dai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. hieu van bac ((dac ban) OR (dac san)) hanh dai ((cua tre) or (cua te))*.