One of the latest was David Phillips' very thorough research into the history of the Church's views on the head covering,
Another source that was important in getting this blog up and running was Brian Schwertley's article, Head Coverings in Public Worship. He also has a series of sermons on head covering at Sermon Audio. When I first found his article as I was putting together this blog I had never heard of him, and in fact still hadn't heard of him until very recently when I was reading Rosaria Butterfield's book about her conversion, where she mentions the effect of his Reformed theology on her understanding of the worship practices in her Reformed Presbyterian Church. That gave him a very welcome identity as a Reformed theologian, which to my mind is a solid recommendation and I wanted to put up a reminder of his contribution on this blog.