Helgason, K. Physical Cosmology, MPI for Astrophysics, Max Planck Society;
Abdollahi, S., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., et al. (2018). A gamma-ray determination of the Universe’s star formation history. Science, 362(6418), 1031-1035. doi:10.1126/science.aat8123.