1. Gard, S.: Poliomyelitis. Papers and discussions presented at the third international poliomyelitis conference, 202, 1955 (Lippincott).
2. Gard, S.: European Assoc. against Poliomyelitis, 3rd Symposium (Zürich), 29?30, 1955
3. Lauffer, M. A. andM. Wheatley: Arch. Biochem.8, 265 (1945).
4. Neumüller, C.: Nature174, 405 (1954).
5. Salk, J. E.: Amer. J. Publ. Health,46, 1 (1956).