The Hulk vs Silver Surfer is from the Hulk 1979 Marvel Calendar and the Spider-Man is from the 1978 Spider-Man Calendar.

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MARVEL 1978 SPIDER-MAN CALENDAR (1978), art by George Pérez and Pablo Marcus, published in MARVEL 1978 SPIDER-MAN CALENDAR, scan from Frank Strysik

MARVEL 1979 HULK CALENDAR (1979), published in MARVEL 1979 HULK CALENDAR, scan from Frank Strysik