..I would say your best bet has to be the Mombeek JG 4 (Vol II) and JG 5 (Vol II) books - I haven't looked to see if he appears in Girbig's JG 5 history... I shouldn't think there's much out there though...he was
Staffelkapitaen of 5./JG 5 during 1942 until early 1944 and served as an instructor for a number of months prior to being appointed to command II./JG 5 - the future IV./JG 4- in September 1944. He had achieved around twelve victories by then..info on Erik's books from
http://www.luftwaffe.be
He gets the briefest of mentions in a letter extract from IV./JG 4 pilot Ernst Scheufele which I translated and posted on my site
http://members.aol.com/falkeeins