Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
danh dau » lanh dao, hang dau, danh tu
dau cua » dai cua, day cua, cau cua
sach ty » sach y, sach tu, sach thu
te sach » toc sach
cao hoc » co hoc, cho hoc, chat hoc
cao hoi » cau hoi, co hoi, tao hoi
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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 ty nang ((cao hoi) OR (cao hoc)). hieu vien bach ((xuc va) or (tuc va)) danh dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ((cao hoi) OR (cao hoc)). hieu vien bach ((xuc va) OR (tuc va)) danh dau cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty nang ((cao hoi) OR (cao hoc)). hieu vien bach ((xuc va) or (tuc va)) danh dau cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ((cao hoi) OR (cao hoc)). hieu vien bach ((xuc va) or (tuc va)) danh dau cua tre*.