Perhaps you should try some spelling variations:
khien canh » thien chanh, hien hanh, bien canh
trinh vat » trinh van, trinh luat, sinh vat
tu sach » thu sach, su sach, tu cach
te sach » toc sach
vat cuu » vat cua
cuu tre » cua tre, cau tren, cau treo
xu may » tu may
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: ((tu sach) OR (te sach)) ky nang x hoi. dieu khien canh ((xu may) or (xe may)) trinh vat cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang x hoi. dieu khien canh ((xu may) OR (xe may)) trinh vat cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky nang x hoi. dieu khien canh ((xu may) or (xe may)) trinh vat cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky nang x hoi. dieu khien canh ((xu may) or (xe may)) trinh vat cuu tre*.