This issue has variants.
Disputed inker credit--Tom Palmer per Steve Whitaker, Nick Caputo, Carl Gafford, and Bob Ford; Neal Adams per the original indexer. Also crediting Adams with inks are The Marvel Comics Index (Olshevsky 1981), 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).
The X-Men logo created by Jim Steranko in issue #50 is adjusted a bit beginning with this issue to become the standard version. Who did this adjustment is in dispute.
Letters (excluding the logo) are credited to Adams in The Official Marvel Index to the X-Men (1987) and Official Index to the Marvel Universe.
Includes a letter from Don McGregor