Graebe; Caro Justus Liebigs Annalen der Chemie, 1871 , vol. 158, p. 275 Full Text Show Details Jensen; Friedrich Journal of the American Chemical Society, 1927 , vol. 49, p. 1051 Full Text Show Details Lehmstedt Chemische Berichte, 1927 , vol. 60, p. 1370 Chemische Berichte, 1931 , vol. 64, p. 2383