https://en.m.wikipedia.org/wiki/Starship_Troopers

https://www.thegreatcourses.com/courses/36-revolutionary-figures-of-history.html

https://www.amazon.com/Cosmos-Possible-Worlds-Ann-Druyan/dp/1426219083

The Door into Summer is a science fiction novel by American writer Robert A. Heinlein, originally serialized in The Magazine of Fantasy & Science Fiction (October, November, December 1956, with covers and interior illustrations by Kelly Freas). It was published in hardcover in 1957. The novel is largely hard science fiction, but includes elements of fantasy and a romance.

Its title was triggered by a remark which Heinlein’s wife Virginia made when their cat refused to leave the house: “He’s looking for a door into summer.” Heinlein wrote the novel in 13 days.

https://en.wikipedia.org/wiki/The_Door_into_Summer