Wall St. Journal:  “The heirs of late comic-book creator Jack Kirby served 45 copyright-termination notices to Marvel Entertainment Inc., Walt Disney Co. and other Hollywood studios relating to comic-book characters and stories created by Mr. Kirby, including ‘X-Men’ and ‘The Fantastic Four.'”

See also the New York Times story “After Disney-Marvel Deal, Cartoonist’s Heirs Seek to Reclaim Rights.”