Observations on Short-toed Eagles nest in 1972
• IRIBARRER, J.J. and RODRÍGUEZ-ARBELOA, A.., 1973 – Observaciones en un nido del Águila Culebrera (Circaetus gallicus), Navarra 1972 [Observations on a nest of Short-toed Eagle, Navarra 1972] // Ardeola 19(1), 101-106. – (Es) /map/.
The text was published in 1973 including some black-and-white images. The placed PDF file is not of the best quality, but it’s fairly readable.