In The Lutheran Liturgy, Dr. Reed mentions that he had physical access to three pre-Reformation missals of Germany: Nuremberg 1484, Bamberg 1498, and Constance 1505 (p. 463). The missals were housed in the Krauth Memorial Library at Philadelphia and supplied the historic basis for the Common Service.
In this regard the internet has changed our world for the better, as libraries across the world digitize the contents of their rare book rooms and make them available to anyone with internet access. One such digital repository is Usuarium, led by Dr. Miklós István Földváry. This project, based out of Hungary, has the ambitious goal of cataloging representative samples of every type of medieval Western liturgy.
I reached out to Dr. Földváry with a question about the Palm Sunday Procession, the subject of his dissertation. He responded by generously giving us access to the entire Usuariam dataset, representing thousands of man-hours and cataloging efforts by himself and his team. Suddenly, we were drowning in historicity, having not three, or even half a dozen sources to consult, but hundreds—too many, in fact. Along with access to PDFs of the original manuscripts, were hundreds of thousands of entries cataloging feast and saint days, special masses and ceremonies, and the Latin incipits for each element of each mass in the temporal cycle.
The Usuarium project is huge, and perhaps years away from being completed, but Dr. Földváry had always envisioned collaboration on an international level. To that end he readily agreed to coordinate the future efforts of our teams and share our research as both projects move forward.