Simon, Klaus, and Herbert Ullrich. 1976. “Biological-Social Problems of Anthropogenesis and Early Human Evolution. Contribution to the Discussion ‘Pre- and Protohistory and the Problem of Historical Periodization’”. EAZ – Ethnographisch-Archaeologische Zeitschrift 17 (1):33-43. https://doi.org/10.54799/RUJU7192.