Cita APA (7th ed.)

Ullrich, F., & Schwalm, H. (2011). Legacy swarm for the Ruhrgebiet: Bob Braine, Mark Dion & GFLK Surveys. Kettler.

Cita Chicago (17th ed.)

Ullrich, Ferdinand, i Hans-Jürgen Schwalm. Legacy Swarm for the Ruhrgebiet: Bob Braine, Mark Dion & GFLK Surveys. Bönen: Kettler, 2011.

Cita MLA (8th ed.)

Ullrich, Ferdinand, i Hans-Jürgen Schwalm. Legacy Swarm for the Ruhrgebiet: Bob Braine, Mark Dion & GFLK Surveys. Kettler, 2011.