Kirk, John G. Division Prof. Dr. Werner Hofmann, MPI for Nuclear Physics, Max Planck Society;
Maccione, L., Liberati, S., Celotti, A., Kirk, J. G., & Ubertini, P. (2008). Gamma-ray polarization constraints on Planck scale violations of special relativity. Physical Review D, 78(10): 103003, pp. 1-5. doi:10.1103/PhysRevD.78.103003.