Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
luoc van » luoc can, luoc va, luot van
te sach » toc sach
cao hoi » cau hoi, co hoi, tao hoi
cao hoc » co hoc, cho hoc, chat hoc
luc van » luu van, duc van, luc va
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 hoi) or (cao hoc)). hieu van nam ((luc van) OR (luoc van)) anh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((cao hoi) OR (cao hoc)). hieu van nam ((luc van) OR (luoc van)) anh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((cao hoi) or (cao hoc)). hieu van nam ((luc van) OR (luoc van)) anh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((cao hoi) or (cao hoc)). hieu van nam ((luc van) OR (luoc van)) anh vi cua tre*.