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 duc » nam duoc, pham duc, nam thuc
duc van » duc va, duc tan, duc manh
van anh » van thanh, tuan anh, van minh
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
y nang » ky nang, ly nang, v nang
anh vi » hanh vi, anh va, anh ve

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 duc van anh vi ((cuu tre) OR (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 duc van anh vi ((cuu tre) OR (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 duc van anh vi ((cuu tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((cao hoi) or (chat hoc)). hieu van nam duc van anh vi ((cuu tre) OR (cua tre))*.