Binder, P. (1976). Siemens crosspoint system ESK 400 E: Capacity stages 20-150-17 and 60-400-36. Siemens Aktiengesellschaft.
Cita Chicago (17th ed.)Binder, Peter. Siemens Crosspoint System ESK 400 E: Capacity Stages 20-150-17 and 60-400-36. Berlín: Siemens Aktiengesellschaft, 1976.
Cita MLA (9th ed.)Binder, Peter. Siemens Crosspoint System ESK 400 E: Capacity Stages 20-150-17 and 60-400-36. Siemens Aktiengesellschaft, 1976.
Atenció: Aquestes cites poden no estar 100% correctes.