[ELS]

A couple of different search results on the Christian Classics Web site:

The First Epistle of Clement to the Corinthians

The Letter of the Church of Rome to the Church of Corinth, Commonly Called Clement's First Letter

[Cicero]

I have a combined volume of the Epistles of Clement and writings of Ignatius of Antioch in the Ancient Christian Writers series, which I bought when I was at college many years ago. It's a nice series, well translated and printed.