documents needed at port of entry for second visit to USA with L1B visa

[thiyagacfd]

Hi,
I have an L1B visa with multple entry valid until 2016.
I visited USA in 2012 for couple of months and will be visiting this year with the same L1B visa (valid I-797, still employed with the same company,etc.) what are the documents that are required at the Immigration entry point at US?
thanks for your time..