What docs are needed for refiling the unused H1B petition

Employer X has been filed my H1B in apr’2011. It was approved by aug’2012. For some project related issues, my visa stamping process didnt iniate and my petition got expired in jul’2013. Except the petition#, I am not having any docs with me. Now, I want to refile my unused H1B through some empllyer Y. Will that petition# alone do good to initiate the refiling process? Please do let me know the options that I have ? Thanks in advance!