1. Kennedy O, Thornes RD (1997) Coumarins: biology, applications and mode of action. Wiley and Sons, Chichester
2. Zahradnik M (1990) The production and application of fluorescent brightening agents, Wiley and Sons
3. Murray RDH, Mendez J, Brown SA (1982) The natural coumarins: occurrence, chemistry and biochemistry. Wiley and Sons, New York
4. von Pechmann H, Duisberg C (1884) Chem Ber 17:929
5. Johnson JR (1942) Org React 1:210