Sources for letters credit are The Official Marvel Index to the X-Men (Olshevsky 1987), The Official Marvel Index to the X-Men (Ward 1994), and Official Index to the Marvel Universe (Vandal et al. 2009). Copy of the cover sketch can be found on http://themarvelageofcomics.tumblr.com
Panel 1 of page 20 cut to make room for Statement of Ownership, which appears at bottom of page.
Total No. Copies Printed (net press run): Average no. copies each issue during preceding 12 months: 339,506