Since they contain some of our oldest copies of Christian and classical writings, early Greek and Latin codices—defined for the sake of this project as those created between about the second and the seventh centuries CE—are typically regarded as individually significant. Collectively, nevertheless, these publications also hold the potential to shed light on the evolution and dissemination of codex technology. The Typology of the Early Codex, a ground-breaking work written by Eric G. Turner and released in 1977, was the final attempt at a thorough analysis of early codices. My primary goal is to examine the Codexes of the Gospel of John. How can I start a study of this kind? What codexes does Logos Bible Software use for the Gospel of John?