Underlying particle spectrum of Mkn 421 during the huge X-ray flare in April 2013A. Sinha, A. Shukla, R. Misra, V. R. Chitnis, A. R. Rao and B. S. AcharyaA&A, 580 (2015) A100DOI: https://doi.org/10.1051/0004-6361/201526264
