Hobbs, R. C., & Smithson, R. (1981). Robert Smithson: Sculpture / Robert Carleton Hobbs. With contrib. by. Cornell Univ. Press.
Čikaški stil citiranja (17. izdanje)Hobbs, Robert Carleton, i Robert Smithson. Robert Smithson: Sculpture / Robert Carleton Hobbs. With Contrib. by. Ithaca [u.a.]: Cornell Univ. Press, 1981.
MLA način citiranja (8. izdanje)Hobbs, Robert Carleton, i Robert Smithson. Robert Smithson: Sculpture / Robert Carleton Hobbs. With Contrib. by. Cornell Univ. Press, 1981.
Upozorenje: Ovi citati možda nisu uvijek 100% točni.