Didelot, X., Achtman, M., Parkhill, J., Thomson, N. R., & Falush, D. (2007). A bimodal pattern of relatedness between the Salmonella Paratyphi A and Typhi genomes: Convergence or divergence by homologous recombination? Genome Research, 17(1), 61-68. doi:10.1101/gr.5512906.