The name of main character of this movie, a man forced to become a double of Francisco Franco, is Paulino which was Franco's real second name.
Franco mentions how his favorite radio host is Matías Prats, who voiced the news bulletins. Prats voices himself in this movie.
"Operation Janus" (to provide Franco with a double) is named after Roman god Janus, who had a second face on the back of his head. Alberto Sinsoles, in charge of Operation Janus, has in his office a bust with one face on each side - but both faces are Franco's.
Generalissimo Franco, Head of State of Spain, says the line "Do as I do: Don't get involved in politics", which, with slight modifications, had been repeated by Emilia throughout the movie. That line is a historical quote by Franco.