^Fehr AR, Perlman S (2015). "Coronaviruses: An Overview of Their Replication and Pathogenesis". In Maier HJ, Bickerton E, Britton P (eds.). Coronaviruses. Methods in Molecular Biology. Vol. 1282. Springer. pp. 1–23. doi:10.1007/978-1-4939-2438-7_1. ISBN978-1-4939-2438-7. PMC4369385. PMID25720466. See Table 1.
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^Woo, Patrick C. Y.; Huang, Yi; Lau, Susanna K. P.; Yuen, Kwok-Yung (2010-08-24). "Coronavirus Genomics and Bioinformatics Analysis". Viruses. 2 (8): 1804–1820. doi:10.3390/v2081803. ISSN1999-4915. PMC3185738. PMID21994708. Figure 2. Phylogenetic analysis of RNA-dependent RNA polymerases (Pol) of coronaviruses with complete genome sequences available. The tree was constructed by the neighbor-joining method and rooted using Breda virus polyprotein.