X-Men #30 1967
X-Men #34 1967
X-Men #36 1967
X-Men #44 1968 Angel
X-Men #50 CGC 9.8 OW/W Pages 2nd appearance of Polaris. Mesmero appearance. Origin of the Beast. New X-Men logo. Classic Steranko Cover
X-Men #60 1969 First appearance of Sauron (Alter Ego of Karl Lykos)
X-Men #64 1970 First appearance of Sunfire
X-Men #67 1970
X-Men #74 1972
X-Men #90 1974
X-Men #93 1975
X-Men #95 1975 Death of Thunderbird; Third appearance of Storm; Third appearance of Nightcrawler; Third appearance of Colossus; Fourth appearance of Wolverine
X-Men #96 1975 1st Appearance of Moira Mactaggert
X-Men #96 CGC 9.8 White Pages (12/75) 1st appearance of Moira MacTaggert.
X-Men #97 1976
X-Men Annual #5 1981 (Newsstand Edition) Variant
X-Men Annual #6 1982 (Newsstand Edition) Variant
