I am in the process of reviewing Georg Walser's monograph, Old Testament Quotations in Hebrews for RBL. In trying to find something out about the author, I discovered that his dissertation is available online:
"Textual and Contextual Background of the Old Testament Quotations in Hebrews." Ph.D. diss., University of Leicester, 2013.
His monograph is a slightly revised version of the dissertation. Naturally, I am adding a link to this dissertation on my theses and dissertations page.
A partial preview of his monograph can be found on the Google Books site.