Stiefel, A., Mahren, S., Ochs, M., Schindler, P. T., Enz, S., & Braun, V. (2001). Control of the Ferric Citrate Transport System of Escherichia coli: Mutations in Region 2.1 of the FecI Extracytoplasmic-Function Sigma Factor Suppress Mutations in the FecR Transmembrane Regulatory Protein. American Society for Microbiology.

Stiefel, Alfred, Susanne Mahren, Martina Ochs, Petra T. Schindler, Sabine Enz, and Volkmar Braun. Control of the Ferric Citrate Transport System of Escherichia Coli: Mutations in Region 2.1 of the FecI Extracytoplasmic-Function Sigma Factor Suppress Mutations in the FecR Transmembrane Regulatory Protein. American Society for Microbiology, 2001.

Stiefel, Alfred, et al. Control of the Ferric Citrate Transport System of Escherichia Coli: Mutations in Region 2.1 of the FecI Extracytoplasmic-Function Sigma Factor Suppress Mutations in the FecR Transmembrane Regulatory Protein. American Society for Microbiology, 2001.