Journal of the Society for Psychical Research

Vol. 4, London 1889.

Proceedings of the Society for Psychical Research

Vol. 6, London 1889.

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 abril 1889, pp. 721-732.