1. R. W. Base, The analysis and synthesis of relay servomechanisms, Sec. III of Final Report, Contract DA-36-034-ORD-1273RD, The Johns Hopkins Institute for Cooperative Research, Baltimore, Md., 1955
2. R. W. Bass, Improved on-off missile stabilization, (to appear)
3. Annals of Mathematics Studies, No. 14;Lefschetz, Solomon,1946
4. I. Flügge-Lotz, Discontinuous automatic control, Princeton University Press, Princeton, N. J., 1954