1. Baver, D.J. (1938). J. Physiol. (London) 93, 90–103.
2. Benninghoff, A. and Spanner, R. (1929). Morph. Jb. 61, 38.
3. Cleary, E.G. (1963). Thesis for M.D., University of Sydney, Australia.
4. Dawes, G.S., Handler, J.J. & Mott, J.C. (1957). J. Physiol. (London) 139, 123–136.
5. Fischer, G.M. and Llaurado, J.G. (1966). Circ. Res. 19, 394–399.