Improved linear system simulation by matrix exponentiation with generalized order hold

Kohr R.H. On the identification of linear and nonlinear systems Simulation vol 8 no 3 March 1967 pp 165-174

Ogata K. State space analysis of control systems Prentice-Hall 1967 p 311

Ragazzini J.R. Franklin G.F. Sampled-data control systems McGraw-Hill 1958 p 34

Hohn F.E. Elementary matrix algebra Macmillan 1964 p 70

The Paynter delay line The Lightning Empiricist vol 11 no 3 July 1963 pp 10-11