What documents are required for I-140?

[vishwambhar]

A friend of mine is using his co-workers Labor Certificate and filling his I-140.
What documents he need to provide to INS in order to use co-workers Labor?
Time is running out for him.
Thanks in advance for your help.

[rkomandur]

Re :What documents are required for I-140?

You can refer to any immigration websites for the supporting documents. But to use already approved labor, it needs to be proved that the job description is same, location etc.,