Sibum, H. O. Exploring the margins of precision: H. Otto Sibum. Natural standards.(2001).
Lua i Stíl Chicago (17ú heag.)Sibum, H. Otto. "Exploring the Margins of Precision: H. Otto Sibum." Natural Standards.(2001) .
Lua MLA (8ú heag.)Sibum, H. Otto. "Exploring the Margins of Precision: H. Otto Sibum." Natural Standards.(2001), .
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.