The New Palgrave Dictionary of Economics, p. 11570-11575, 2018
DOI: 10.1057/978-1-349-95189-5_1980
The New Palgrave Dictionary of Economics, 2012 Version
DOI: 10.1057/9781137336583.1535
The New Palgrave Dictionary of Economics, p. 112-115
DOI: 10.1057/9780230226203.1425