Carl Du Prel

The philosophy of mysticism

George Redway, London 1889.

Joseph Jastrow

The psychology of spiritualism

The Popular Science Monthly, N. 46, Vol. XXXIV, London aprile 1889, pp. 721-732.

Proceedings of the Society for Psychical Research

Vol. 6, London 1889.

Proceedings of the Society for Psychical Research

Vol. 6, London 1889.

Journal of the Society for Psychical Research

Vol. 4, London 1889.

Niceforo Filatete e Vincenzo Scarpa

Annali dello spiritismo in Italia

Vol. 27-28, Tipografia A. Baglione, Torino 1890.

Proceedings of the Society for Psychical Research

Vol. 7, London 1891.

Journal of the Society for Psychical Research

Vol. 5, London 1891.

Edmund Gurney, Frederic William Henry Myers, e Frank Podmore

Les hallucinations télépathiques

Félix Alcan, Paris 1891.

Proceedings of the Society for Psychical Research

Vol. 8, London 1892.