Stephen J. Shoemaker is Professor of Religious Studies and Ira E. Gaston Fellow in Christian Studies at the University of Oregon. He has written a number of books but a recent book "Creating the Qur'an. A Historical-critical Study" has caused quite a stir.
In this book he covers a number of subjects that are revelant to how the Quran came into being. Included is a study in radio carbon dating, whether the Quran was canonised by Uthman or joinly by Abd al-Malik and al-Hajjaj, what do we learn from memory science, the levels of literacy in Muhammad's time and many other important subjects.
His conclusions present a big issue for Islam's standard Islamic narrative regarding the creation of the Quran. There are some challenging questions that Islam has to respond to.
Shoemaker has graciously made his book available for free (and it is not a particularly expensive book to buy either) and can be downloaded from his Academia page. Available here.
The video below is Shoemaker in discussion with Gabriel said Reynolds on his YouTube channel, Exploring the Quran and the Bible.