 John Hill maintains that "the Periplus can now be confidently dated to between  40 and 70 AD and, probably, between AD 40 and 50."
<coherence>  John Hill maintains that "the Periplus can now be confidently dated to between  40 and 70 AD and, probably, between AD 40 and 50."
 John Hill maintains that "the Periplus can now be confidently dated to between 40 and 70 and, probably, between AD 40 and 50."