1. Todd, Brit. J. Exp. Path., 8, 369 (1927).
2. Olitski, Boëz, J. Exp. Med., 45, 685 (1927).
3. Douglas, Wilson-Smith, Brit. J. Exp. Path., 9, 213 (1928).
4. Kligler, Olitski, Brit. J. Exp. Path., 12, 69 (1931).
5. Olitski, Long, J. Exp. Med., 50, 263 (1929).