Generalization of amplitude phase and accompanying differential equation Miloš Háčik (1971) Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica-Physica-Chemica Similarity:
Algebraic definition of central dispersions of the 1st kind of the differential equation y ' ' = Q ( t ) y Erich Barvínek (1966) Czechoslovak Mathematical Journal Similarity: