Two-dimensional electronic spectroscopy of graphene nanoribbons in organic solutionTetsuhiko Nagahara, Lucia Ganzer, V. A. Camargo Franco, Yinjuan Huang, Fugui Xu, Yiyong Mai, Giulio Cerullo and Xinliang FengEPJ Web Conf., 205 (2019) 05005DOI: https://doi.org/10.1051/epjconf/201920505005