Wintering in Spain and habitat in Greece
Here you can acquaint yourself with the work on the wintering of Short-toed Eagle and Booted Eagle in Spain:
• José Enrique Martínes y José Antonio Sánchez-Zapata, 1999 – Invernada de Aguililla Calzada (Hieraaetus pennatus) y Culebrera Europea (Circaetus gallicus) en España // Ardeola 46(1): 93-96 – 
(Es)
(source – Ardeola website).
…and with abstract of the article about the Greek Short-toed Eagles:
• D.E. Bakaloudis, C.G. Vlachos, G.J. Holloway, 1998 – Habitat Use by Short-Toed Eagles Circaetus gallicus and Their Reptilian Prey During the Breeding Season in Dadia Forest (North-Eastern Greece) // Journal of Applied Ecology, Vol. 35, No. 6: 821-828 (En) /map/
(source – the JSTOR database).