The special case of Bootstrap Paradox in which a guy travels back in time to protect himself is common these days. I have encountered it countless times.
The first example I encountered was in Shaktimaan (90slate 90s) episodeEpisode 227 (jump to 24:11) in which the superhero travelled back in time to protect his mother and his child-self from his arch nemesis Kilvish.
The most recent I encountered:
In The Flash (2014) TV series, Flash from the future travelled back in time to protect himself from Reverse Flash.
In The Flash (2014) TV series, Flash from the future travelled back in time to protect his child-self from Reverse Flash.
Which Sci-Fi work introduced this idea to the world?