Spiess, E., Bestvater, F., Heckel-Pompey, A., Toth, K., Hacker, M., Stobrawa, G., et al. (2005). Two-photon excitation and emission spectra of the green fluorescent protein variants ECFP, EGFP and EYFP. Journal of Microscopy, 217(3): 1, pp. 200-204. Retrieved from http://dx.doi.org/10.1111/j.1365-2818.2005.01437.x.