What is the film that they say Alien was based on?

From wiki:

In writing the script, O'Bannon drew inspiration from many previous works of science fiction and horror. He later stated,"I didn't steal Alien from anybody. I stole it from everybody!"[32] The Thing from Another World (1951) inspired the idea of professional men being pursued by a deadly alien creature through a claustrophobic environment.[32] Forbidden Planet (1956) gave O'Bannon the idea of a ship being warned not to land, and then the crew being killed one by one by a mysterious creature when they defy the warning.[32] Planet of the Vampires (1965) contains a scene in which the heroes discover a giant alien skeleton; this influenced the Nostromo crew's discovery of the alien creature in the derelict spacecraft.[32] O'Bannon has also noted the influence of "Junkyard" (1953), a short story by Clifford D. Simak in which a crew lands on an asteroid and discovers a chamber full of eggs.[27] He has also cited as influences Strange Relations by Philip José Farmer (1960), which covers alien reproduction, and various EC Comics horror titles carrying stories in which monsters eat their way out of people.[27]