Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
hieu vien » hieu viec, thieu nien, hieu tieng
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach
cac dai » cac dan, cac bai, can dai
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, vu khach
nang o » nang co, nang ho, nang ro
dai va » mai va
vi cua » vai cua, di cua
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (vu sach)) ky nang o hoi. ((hieu vien) or (hieu hien)) cac dai va thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ky nang o hoi. ((hieu vien) OR (hieu hien)) cac dai va thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ky nang o hoi. ((hieu vien) or (hieu hien)) cac dai va thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ky nang o hoi. ((hieu vien) or (hieu hien)) cac dai va thanh vi cua tre*.