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2. E. Morselli. Psychology and Spiritism (in Italian). Fr. Bocca, Turin, 1908.
3. C. de Vesme. "The Thinking Horses of Elberfeld" (in French). Annales des Sciences Psychiques, XXII, 12. Paris, 1910.
4. G. C. Ferrari and F. Pulle. "The First Month of a Horse's Education" (in Italian). Rivista di Psicologia, March-April, 1913.
5. E. C. Sanford. "Psychic Research in the Animal Field." American Journal of Psychology, XXV, 1914.
6. P. Sarasin. "Animal and Human Quick Reckoners" (in German), from Proceedings of the Natural History Society at Basle. Basle, 1915.
7. H. E. Ziegler. The Soul of the Animal (in German). W. Junk, Berlin, 1916.
8. W. Neumann. "Pseudo-animal-psychology" (in German), from Naturwiss: Wochenschrift. Jena, 1916.
9. W. Mackenzie. At the Founts of Life (in Italian). A. F. Formiggini, Rome, 1916. (Out of print).
10. W. Maeterlinck. The Unknown Guest. Methuen, London.