Avdievich, N., Jeevarajan, A., & Forbes, M. (1996). Photoionization of N,N,N‘,N‘-Tetramethylphenylenediamine
Studied by Q-Band Time-Resolved EPR Spectroscopy: Separation of Singlet and Triplet Ionization Channels.
The Journal of Physical Chemistry, 100(13), 5334-5342. doi:10.1021/jp952314s.