Henkel, G. (1995). Philip Johnson: Homo ludens. Augenblicke : Interviews - Reviews - Views.
Lua i Stíl Chicago (17ú heag.)Henkel, Gabriele. "Philip Johnson: Homo Ludens." Augenblicke : Interviews - Reviews - Views 1995.
Lua MLA (8ú heag.)Henkel, Gabriele. "Philip Johnson: Homo Ludens." Augenblicke : Interviews - Reviews - Views, 1995.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.