Herscovici, A. “Keynes and the Concept of Capital: Some Epistemological Observations in Regard to the Sraffian Premises of the General Theory: ”. Brazilian Journal of Political Economy, vol. 33, no. 3, July 2013, pp. 486-04, https://centrodeeconomiapolitica.org.br/repojs/index.php/journal/article/view/324.