{12}Nicholas G.Blurton Jones et al.,'Antiquity of Postreproductive Life:Are There Modern Impact on Hunter-Gatherer Postreproductive Life Spans',American Journal of Human Biology 14(2002),184-205.

{13}Kim Hill and A.Magdalena Hurtado,AchéLife History:The Ecology and Demography of a Foraging People (New York:Aldine de Gruyter,1996),164,236.

{14}Hill and Hurtado,AchéLife History,78.

{15}Vincenzo Formicola and Alexandra P.Buzhilova,'Double Child Burial from Sunghir (Russia):Pathology and Inferences for Upper Paleolithic Funerary Practices',American Journal of Physical Anthropology 124:3(2004),189-98;Giacomo Giacobini,'Richness and Diversity of Burial Rituals in the Upper Paleolithic',Diogenes 54:2(2007),19-39.

{16}I.J.N.Thorpe,'Anthropology,Archaeology,and the Origin of Warfare',World Archaology 35:1(2003),145-65;Raymond C.Kelly,Warless Societies and the Origin of War (Ann Arbor:University of Michigan Press,2000);Azar Gat,War in Human Civilization (Oxford:Oxford University Press,2006);Lawrence H.Keeley,War before Civilization:The Myth of the Peaceful Savage (Oxford:Oxford University Press,1996);Slavomil Vencl,'Stone Age Warfare',in Ancient Warfare:Archaeological Perspectives,ed.John Carman and Anthony Harding (Stroud:Sutton Publishing,1999),57-73.