Our paper, “Strong photon-magnon coupling using a lithographically defined organic ferrimagnet,” by Qin Xu, Hil Fung Harry Cheung, Donley S. Cormode, Tharnier O. Puel, Huma Yusuf, Michael Chilcote, Michael E. Flatté, Ezekiel Johnston-Halperin, and Gregory D. Fuchs is now out on the arXiv.