Imakawa, K.; Nakagawa, S. (2017). "The Phylogeny of Placental Evolution Through Dynamic Integrations of Retrotransposons". Molecular Biology of Placental Development and Disease. Progress in Molecular Biology and Translational Science. Vol. 145. pp. 89–109. doi:10.1016/bs.pmbts.2016.12.004. ISBN978-0-12-809327-6. PMID28110755.
Imakawa, K.; Nakagawa, S. (2017). "The Phylogeny of Placental Evolution Through Dynamic Integrations of Retrotransposons". Molecular Biology of Placental Development and Disease. Progress in Molecular Biology and Translational Science. Vol. 145. pp. 89–109. doi:10.1016/bs.pmbts.2016.12.004. ISBN978-0-12-809327-6. PMID28110755.