1. A textbook of physiology, part three: The central nervous system;Foster,1897
2. The nerve cell considered as the basis of neurology;Schäfer;Brain,1893
3. Sherrington, C. S. to Schäfer, E. A., letter 27th Nov 1897, in the Sharpey-Schäfer papers in the Contemporary Medical Archives Centre, the Wellcome Institute for the History of Medicine, reference PP/ESS/B21/8. Copies are also available in the Sherrington Library for the History of Neuroscience, University Laboratory of Physiology, Oxford, and in the Sherrington collection in the Woodward Library, Vancouver.
4. Sherrington, C. S. to Schäfer, E. A., letter 1st Dec. 1897, reference PP/ESS/B21/9, locations as in reference 3.
5. The nerve cell;Schäfer,1900