Ref:KUHN Synthetisches Vitamin B2 DFGRPAIV
De Commission Historique
Weygand, Friedrich;Kuhn, Richard. "Synthetisches Vitamin B2." Berichte der deutschen chemischen Gesellschaft (A and B Series) 67 (1934) : 2084-2085.
http://chemistry.europe.onlinelibrary.wiley.com/doi/abs/10.1002/cber.19340671231
