What do I need to send together with my tax amendment forms?

Hi there,
I already got my refund, but I received an additional W2 from another employer. I amended my taxes and printed all the forms I need to mail to the IRS together with the check for the money I owe after the amendment.

Do I need to send anything else together with the forms (for example the additional W2 copy I received that cause me to amend my taxes? )

Thanks,

AL