Kaiser, R. P.; Mosinger, J.; Císařová, I.; Kotora, M. Synthesis of selectively 4-substituted 9,9 '-spirobifluorenes and modulation of their photophysical properties. Organic & Biomolecular Chemistry 2017, 15 (33), 6913-6920 DOI: 10.1039/c7ob01319a.