Ortega Huertas, M., F. Martínez Ruiz, P. Acquafredda, y I. Palomo. 1994. «Platinum-Group Elements in the Cores of Potassium Feldspar Spherules from the Cretaceous-Tertiary Boundary at Caravaca (Spain)». Estudios Geológicos 50 (1-2):3-7. https://doi.org/10.3989/egeol.94501-2303.