Kaufmann, Moritz:

Utopias: or, Schemes of Social Improvement, from Sir Thomas More to Karl Marx,

London, 1879.

Nettlau, Max:

Bibliographie de L’Anarchie, (Utopies Libertaires), Paris, 1897.

Hoffding, Harald:

A History of Modern Philosophy,

translated by B. E. Meyer, London, 1900.

Kropotkin, Peter:

The Conquest of Bread,

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