Action spectroscopy of isomer-selected luciferin anions Christina Kjær, James N. Bull, Eduardo Carrascosa, Steen Brøndsted Nielsen and Evan J. Bieske Eur. Phys. J. D, 75 3 (2021) 72 Published online: 02 March 2021 DOI: 10.1140/epjd/s10053-021-00076-w