King, S., Cass, M., Pintani, M., Coward, C., Dias, F., Monkman, A., & Roberts, M. (2011). The contribution of triplet-triplet annihilation to the lifetime and efficiency of fluorescent polymer organic light emitting diodes. Journal of Applied Physics, 109(7), Article 074502. https://doi.org/10.1063/1.3561430