Cita APA (7a ed.)

Brockhaus, C., Ruhrberg, K., & Schumacher, E. (1987). Emil Schumacher: Text : Christoph Brockhaus, Karl Ruhrberg, Emil Schumacher. DSL Bank.

Cita Chicago Style (17a ed.)

Brockhaus, Christoph, Karl Ruhrberg, y Emil Schumacher. Emil Schumacher: Text : Christoph Brockhaus, Karl Ruhrberg, Emil Schumacher. Bonn: DSL Bank, 1987.

Cita MLA (8a ed.)

Brockhaus, Christoph, et al. Emil Schumacher: Text : Christoph Brockhaus, Karl Ruhrberg, Emil Schumacher. DSL Bank, 1987.