Given the following context:

Curtis was the band's sole lyricist, and he typically composed his lyrics in a notebook, independently of the eventual music to evolve. The music itself was largely written by Sumner and Hook as the group jammed during rehearsals. Curtis's imagery and word choice often referenced "coldness, pressure, darkness, crisis, failure, collapse, loss of control". In 1979, NME journalist Paul Rambali wrote, "The themes of Joy Division's music are sorrowful, painful and sometimes deeply sad." Music journalist Jon Savage wrote that "Curtis's great lyrical achievement was to capture the underlying reality of a society in turmoil, and to make it both universal and personal," while noting that "the lyrics reflected, in mood and approach, his interest in romantic and science-fiction literature." Critic Robert Palmer wrote that William S. Burroughs and J. G. Ballard were "obvious influences" to Curtis, and Morris also remembered the singer reading T. S. Eliot. Deborah Curtis also remembered Curtis reading works by writers such as Fyodor Dostoevsky, Friedrich Nietzsche, Jean-Paul Sartre, Franz Kafka, and Hermann Hesse.Curtis was unwilling to explain the meaning behind his lyrics and Joy Division releases were absent of any lyric sheets. He told the fanzine Printed Noise, "We haven't got a message really; the lyrics are open to interpretation. They're multidimensional. You can read into them what you like." The other Joy Division members have said that at the time, they paid little attention to the contents of Curtis' lyrics. In a 1987 interview with Option, Morris said that they "just thought the songs were sort of sympathetic and more uplifting than depressing. But everyone's got their own opinion." Deborah Curtis recalled that only with the release of Closer did many who were close to the singer realise "[h]is intentions and feelings were all there within the lyrics". The surviving members regret not seeing the warning signs in Curtis's lyrics. Morris said that "it was only after Ian died that we sat down and listened to the...

answer the following question:

What are the last names of the two people who Palmer said were obvious influences to Curtis? 

Ballard