Having just completed their second comeback stage on Music Core for their latest single, NU ABO, the f(x) girls weren't quite done with their schedules as they attended a fan signing event this evening. You can tell that the photographer was a big Sulli fan because he/she got really good shots of her while only normal shots were taken of the other members. Well, I am not complaining since I am a big Sulli fan myself! [gallery]