@book{ BA24866284, author = "Cohen, J. M. (John Michael)", title = "The four voyages of Christopher Columbus : being his own log-book, letters and dispatches with connecting narrative drawn from the Life of the Admiral by his son Hernando Colon and other contemporary historians", publisher = "Penguin", year = "1969", series = "Penguin classics", number = "", URL = "https://ci.nii.ac.jp/ncid/BA24866284" }