Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope. - Ajello M; Albert A; Anderson B; Baldini L; Barbiellini G; Bastieri D; Bellazzini R; Bissaldi E; Blandford RD; Bloom ED; Bonino R; Bottacini E; et al. (Physical review letters, 2016)