References

[1]
S. Lie. Theorie der Transformationsgruppen I. Mathematische Annalen 16, 441–528 (1880).
[2]
H. F. Trotter. On the Product of Semi-Groups of Operators. Proceedings of the American Mathematical Society 10, 545–551 (1959).
[3]
S. K. Godunov. A difference method for numerical calculation of discontinuous solutions of the equations of hydrodynamics. Matematicheskii Sbornik 89, 271–306 (1959).