1. Birkelo, C. C., Chamberlain, W. E., Zacks, D., and Yerushalmy, J. Phelps, (1947).
2. Chodoff. P., Simon, A., and Freeman, W. (1948). Amner. J. Roentgenol., 59, 311.
3. The Nornmal EntcephaloJouirnal of Neuirology, Evans, W. A., Jr. (1942). Arch. Neurol. Psvchiat., Chicago, 47, 931.
4. Heinrich, A. (1939). Z. Altersforsch., 1, 345.
5. LMMyocsrMheelon,!emarn,Fnz.d,eE.yPas,(yn1cd9hW3i.W5ai)tl.rHdyi.,,A4(c,E1t.94a481(.R1)a9.d5i3o)lJ..o,urSSnlcaohlcwkehoi.fz,.NSeAuurprcpohll..ogNXjeX,uIrVoNl.e.urPossycuhrigaetr.y, 72, 211. Rothschild, D., (1941).