Julio was a Puerto Rican who lived on 204th Street in the Inwood neighborhood of Manhattan, and was a member of the Savage Skulls. In 1971 the New York Times published an article about another graffiti writer with similar form, Taki 183. According to the article Julio had been writing for a couple of years when Taki began tagging his own name all around the city. Taki also states in the article that Julio "was busted and stopped". Julio 204 kept his tags localized to his own neighborhood, and never rose to the height of fame as Taki, who was the first to go "All City".
- "Style: Writing from the Underground. (R)evolutions of Aerosol Linguistics", Stampa Alternativa in Association with IGTimes,1997. ISBN 88-7226-318-2.
- "Freight Train Graffiti", Roger Gastman, Ian Sattler, Darin Rowland. Harry N Abrams Inc, 2006. ISBN 978-0-8109-9249-8
- "The Birth of Graffiti", Jon Naar, Prestel 2007. ISBN 978-3-7913-3796-8