Frans de Waal (2013).
131
Mary Midgley (1995) and (2010); Gregory McElwain (2020).
132
Frans de Waal (2006).
133
Inbal Ben-Ami Bartal et al. (2011).
134
Melanie Killen and Elliot Turiel (1991); Cary Roseth (2018).
135
Rutger Bregman (2019).
136
Toni Morrisson (2019).
137
Henry Nicholls (2014).
138
Hans Kummer (1995), p. xviii.
139
Hans Kummer (1995), p. 193; Christian Bachmann and Hans Kummer (1980).
140