W.M. Star, H.P.A. Marijnissen, H. Jansen, M. Keijzer, M.J.C. van Gemert, "Light dosimetry for photodynamic therapy by whole bladder wall irradiation," Photochem. Photobiol. 46:619-624, 1987. J.P. Marijnissen, W.M. Star, "Calibration of isotropic light dosimetry probes based on scattering bulbs in clear media," Phys. Med. Biol. 41:1191-1208, 1996. L. Lilge, T. Haw, B.C. Wilson, "Miniature isotropic optial fibre probes for quantitative light dosimetry in tissue," Phys. Med. Biol. 38:215-230, 1993.