If you can read German, by ALL means check to see if books by Friedrich Brettner are still available!
His research and books specifically focused on German units involved in action between Vienna and Graz at the very end of the war, based on memoirs of those who were there at the time, soldiers as well as civilians. Absolutely invaluable stuff, wish I'd bought every book he wrote when I was there nine years ago.
I have the book "Die Letzten Kaempfe des II. Weltkrieges, Pinka-Lafnitz-Hochwechsel, 1. Gebirgsdivision, 1.Panzerdivision, Divisionsgruppe Krause, 117. Jaegerdivision, Kampfgruppe Arko 3"
Other books he'd written by that time are listed inside the front cover:
"Die letzten Kaempfe des 2. Weltkrieges im Semmering-Gebiet"
"Schicksale mahnen 1938-1955"
"Fuer Heimat, Volk und Ehre"
"Die letzten Kaempfe des 2. Weltkrieges im suedlichen Niederoesterreich"