Perhaps you should try some spelling variations:
dieu hien » dieu khien, dieu kien, bieu hien
bach tuoc » sach duoc, sach nuoc
hieu hien » bieu hien, chieu chien, dieu khien
tu sach » thu sach, su sach, tu cach
va hang » van hang, va nang, va lang
tuoc va » thuoc va, nuoc va, duoc va
cuu tre » cua tre, cau tren, cau treo
nang xa » nang x, lang xa, nang ma
te sach » toc sach
va cuu » va cau, va chu, va huu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) ky nang xa hoi. ((hieu hien) OR (dieu hien)) bach tuoc va hang va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang xa hoi. ((hieu hien) OR (dieu hien)) bach tuoc va hang va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang xa hoi. ((hieu hien) OR (dieu hien)) bach tuoc va hang va cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang xa hoi. ((hieu hien) OR (dieu hien)) bach tuoc va hang va cuu tre*.