1. Garrison F: In An Introduction to the History of Medicine, 3rd ed, WB Saunders, Philadelphia, 1924, p 479.
2. Callan H, Tomlin S: Proc Roy Soc (London) Ser B 137:367–378, 1950.
3. Gall J: Protoplasmatologia 5:4–25, 1964.
4. Gall J: J Cell Biol 32:391–399, 1967.
5. Wischnitzer S: J Ultrastruct Res 1:201–222, 1958.