Perhaps you should try some spelling variations:
chat hoc » chat hoa, chat thom, cho hoc
hieu van » hieu va, thien van, lieu va
te sach » toc sach
cao hoi » cau hoi, co hoi, cao hoc
nam luc » nang luc, nhan luc, nam thuc
luc van » luoc van, luu van, duc van
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
anh vi » hanh vi, anh va, anh vu
anh ve » hanh ve, anh va, anh viet

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 y nang ((cao hoi) or (chat hoc)). hieu van nam luc van ((anh vi) OR (anh ve)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((cao hoi) OR (chat hoc)). hieu van nam luc van ((anh vi) OR (anh ve)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((cao hoi) or (chat hoc)). hieu van nam luc van ((anh vi) OR (anh ve)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((cao hoi) or (chat hoc)). hieu van nam luc van ((anh vi) OR (anh ve)) cua tre*.