From Proto-Indo-European to Proto-Germanic:A Linguistic History of English ... - Donald Ringe - Google Books

http://books.google.de/books?id=seYlebN1UcgC&pg=PA60&lpg=PA60&dq=dHr%C3%B3gHos&source=web&ots=uoVFZqhy0L&sig=UZoRnsnGyBqOtWng4yE

This book describes the earliest reconstructable stages of the prehistory of English. It outlines the grammar of Proto-Indo-European, considers the changes by which one dialect of that prehistoric language developed into Proto-Germanic, and provides a…