So, drawing from:

Linear Control Systems Analysis and Design

Conventional and Modern

Third Edition

John D'Azzo and Constantine Houpis

1988

Development of Digital Aircraft Controls

SAS - Stability Augmentation System

CAS - Command Augmentation System

FBW - Fly By Wire

DFCS - Digital Flight Control System

Laplace Transform and 1932 Nyquist paper on steady-state frequency-response techniques for feedback amplifier design.

Work by Black, H. S. 1934

Bode, H. W. 1945

Hall, A. C. 1946

Harris, H. 1946

Nyquist, H. 1932

Talks about writing system equations, usually LTI, Linear Time Invariant

Talks about Lagrange's Equation

Talks about every kind of system, even electromagnetic with capacitive coupling. Talks about hydraulic actuators.

Talks about thermal, modeled as a circuit, capacitor being charged by a voltage source through a resistor. Then they add a second resistor and capacitor to show heat transfer to something more remote. You could add another resistor, a bleeder, to account for heat losses beyond this.

DeRusso, P. M. et al "State Variables for Engineers", Wiley 1965

State variables for engineers [by] Paul M. DeRusso, Rob J. Roy [and] Charles M. Close (1965)

Blackburn J. F. ed "Components Handbook" McGraw-Hill 1948 ( a book of this type this old would be trip to look at )

Wylie, C. R. jr "Advanced Engineering Mathematics" 4th ed, McGraw-Hill 1975

Wylie, Clarence Raymond, 1911- Advanced engineering mathematics, first edition 1951, only 640 pages

Kinariwala, B. et al "Linear Circuits and Computation" 1973

Gantmacher, F. R. "Applications of the Theory of Matrices" 1959

Gantmakher, F. R. (Feliks Ruvimovich) Applications of the theory of matrices / Translated and rev. by J. L. Brenner, with the assistance of D. W. Bushaw and S. Evanusa New York : Interscience Publishers, 1959

Kalman, R. E. "Mathematical Description of Lineal Dynamical Systems" paper , 1963

^^^ a NASA big wig and a leader in the movement to Stochastic Controls, and for filtering and even for phased locked loops

Kalman, R. E. (Rudolf Emil), 1930-

Topics in mathematical system theory [by] R. E. Kalman, P. L. Falb [and] M. A. Arbib

New York : McGraw-Hill, [1969]

https://en.wikipedia.org/wiki/Rudolf_E._K%C3%A1lm%C3%A1nThe Kalman Filter

http://www.cs.unc.edu/~welch/kalman/