Horvitz, R. J. (1973). Nature As Artifact: Alan Sonfist / von Robert Joseph Horvitz. Artforum.
Lua i Stíl Chicago (17ú heag.)Horvitz, Robert Joseph. "Nature As Artifact: Alan Sonfist / Von Robert Joseph Horvitz." Artforum 1973.
Lua MLA (8ú heag.)Horvitz, Robert Joseph. "Nature As Artifact: Alan Sonfist / Von Robert Joseph Horvitz." Artforum, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.