Beethoven Piano TrosArchived 10 March 2016 at the Wayback Machine discogs.com (The stated recording date, 2 October 1965, must be a typographical error since Kolbe purchased the Leonhard mixing desk in April 1966.)
"{title}"(PDF). Archived(PDF) from the original on 5 March 2016. Retrieved 19 January 2014.
Beethoven Piano TrosArchived 10 March 2016 at the Wayback Machine discogs.com (The stated recording date, 2 October 1965, must be a typographical error since Kolbe purchased the Leonhard mixing desk in April 1966.)