Photodetection of early human bladder cancer based on the fluorescence of 5-aminolaevulinic acid hexylester-induced protoporphyrin IX: a pilot study. - Lange, N; Jichlinski, P; Zellweger, M; Forrer, M; Marti, A; Guillou, L; Kucera, P; Wagnières, G; Bergh, H van den (British Journal of Cancer, 1999)