As to everyone, I look foward to offering you some fresh sources to compliment your 1 book. Give me some time (I am currently busy) and I'll post something.

btw, I agree there are some great books in German on the subject but that does not mean they are inherently more academic or more accurate. Not all books are created equal therefore a comparison of all sources breeds best. Yet I must admit that my favorite book is one that I can only read in German: F. Holthausen's Altenglisches Etymologisches Wörterbuch seems pretty unbeatable in quality. I am sometimes biased in such decisions on scholarship and presentation.