Friis-Hansen, D., & Brettell, R. R. (1996). Richard Long: Circles, Cycles, Mud, Stones.
Lua i Stíl Chicago (17ú heag.)Friis-Hansen, Dana, agus Richard R. Brettell. Richard Long: Circles, Cycles, Mud, Stones. Houston, 1996.
Lua MLA (8ú heag.)Friis-Hansen, Dana, agus Richard R. Brettell. Richard Long: Circles, Cycles, Mud, Stones. 1996.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.