Mayerling: the facts behind the legend /
Judtmann, Fritz.
Osers, Ewald,1917-2011.
London Harrap
1971
Originally published as 'Mayerling ohne Mythos'. Wien (Vienna): Kremayer & Scheriau, 1968
bibl p371-381
Rudolph Crown Prince of Austria.
Vetsera, Marie Alexandrine Baronesse.