Ruf, B., Baldessari, J., Gillick, L., & Weiner, L. (2007). Again the Metaphor Problem and Other Engaged Critical Discourses about Art: A Conversation between John Baldessari, Liam Gillick and Lawrence Weiner, moderated by Beatrix Ruf. Springer.

Ruf, Beatrix, John Baldessari, Liam Gillick, and Lawrence Weiner. Again the Metaphor Problem and Other Engaged Critical Discourses About Art: A Conversation Between John Baldessari, Liam Gillick and Lawrence Weiner, Moderated by Beatrix Ruf. Wien [u.a.]: Springer, 2007.

Ruf, Beatrix, et al. Again the Metaphor Problem and Other Engaged Critical Discourses About Art: A Conversation Between John Baldessari, Liam Gillick and Lawrence Weiner, Moderated by Beatrix Ruf. Springer, 2007.