Christian Gramsch, Gerhard Kleber, Volker Höllt, Aurelio Pasi, Parviz Mehraein, Albert Herz,
Pro-opiocortin fragments in human and rat brain: β-endorphin and α-MSH are the predominant peptides Brain Research. ,vol. 192, pp. 109- 119 ,(1980) ,
10.1016/0006-8993(80)91012-4