These old short texts have been found recently on the Net:
• Bas van Balen, A. R. Compost, 1989 – Overlooked evidence of the Short-toed Eagle Circaetus gallicus on Java // Kukila. Vol. 4 – No 1-2 – P. 44-46. –
(En) /map/;
• Wolfgang Rowold & Harald Weidener, 1999 – Beobachtung eines Schlangenadlers (Circaetus gallicus (Gmel.,1788)) in Marienmünster, Krs. Höxter [Observation of the Short-toed Eagle in Marienmünster] // Egge-Weser. Bd. 12. – S. 61. –
(De) /map/.
And a work on flight properties of Palearctic Eagles, where Short-toed Eagle is one of the research objects:
• Kirmse W., 1998 – Morphometric features characterizing Flight Properties of Palearctic Eagles // Holarctic Birds of Prey. – P. 339-348. –
(En).