According to Augustine Brannigan's "The social basis of scientific 
discoveries", the classical papers on simultaneous discoveries are: 
 
1. A.L. Kroeber(1917): "The superorganic". American Anthropologist, 19 
(2),  p. 163-213. 
 
2. William Ogburn & Dorothy Thomas (1922): "Are inventions inevitable? A 
note on social evolution". Political Science Quarterly, 37 (1), p. 83-98. 
 
Best wishes 
Ramon Garcia Fernandez