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 hoc » co hoc, cho hoc
nam luc » nhan luc, nam thuc, nam duoc
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
anh vi » hanh vi, anh va, anh ve
vi cua » vai cua, di cua

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