Picon
Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1922 , vol. 175, p. 1215;
Bulletin de la Societe Chimique de France, 1923 , vol. <4>33, p. 92
Fishwick, Colin W. G.; Gupta, Ramesh C.; Storr, Richard C.
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1984 , p. 2827 - 2829