I realize that I have not been able to cover all of the texts and traditions on Peter’s ministry and martyrdom in Rome. Thus, I would recommend David L. Eastman’s The Ancient Martyrdom Accounts of Peter and Paul (Atlanta: SBL, 2015). This collects all the key source texts, including ancient martyrdom accounts that have been translated into English for the first time. The table of contents and the introductory chapter have been made available by SBL Press here. There are reviews of this monograph at Bryn Mawr Classical Review and the Catholic Biblical Review.