The poem by Juan Gelman that Lucio recites to his students in literature class is entitled "El juego en que andamos" ('The game we are in') and belongs to the homonymous collection of poems published in 1959.
The daughter and wife of filmmaker Diego Lerman act in the film: Renata Lerman plays Sol, Lucio's teenage daughter; María Merlino is the teacher, co-worker, with whom Lucio establishes a sentimental relationship.