Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
hieu hien » bieu hien, chieu chien, dieu khien
toc sach » hoc sach, doc sach, thuoc sach
bach duc » bach tuoc, sach duoc, thach duc
thanh va » thanh van, hanh va, thanh ha
duc gia » quoc gia
cac tre » cac tro, cac tru, cac trieu
x hoi » xa hoi, o hoi, x ho

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) or (toc sach)) ky nang x hoi. ((hieu hien) OR (dieu hien)) bach duc gia thanh va cac tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang x hoi. ((hieu hien) OR (dieu hien)) bach duc gia thanh va cac tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang x hoi. ((hieu hien) OR (dieu hien)) bach duc gia thanh va cac tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang x hoi. ((hieu hien) OR (dieu hien)) bach duc gia thanh va cac tre*.