(en) Monica Herrera, « Katy Perry: The Billboard Cover Story », Billboard, e5 Global Media, (consulté le ) : « "I love what I get out of them," Perry says of Gottwald and his cohorts. "It's just pure, unabashed pop... »
« Taylor Swift Makes Sparkling Hot 100 Entrance », Billboard, (lire en ligne, consulté le )
(en) James Montgomery, « New Katy Perry Songs Hit The Net », MTV, (consulté le ) : « Each track seems to confirm what Perry has already told MTV News about the new album, mainly that it's a "summer record" filled with bubbly, electro-tinged pop tunes... »
