Bar, G., Bennati, M., Nguyen, H. H., Stubbe, J., & Griffin, R. G. (2001). High-frequency (140-GHz) time domain EPR and ENDOR spectroscopy: The tyrosyl radical-diiron cofactor in ribonucleotide reductase from yeast. Journal of the American Chemical Society, 123(15), 3569-3576. doi:10.1021/ja003108n.