Comments to the problem on branching of periodical solutions at Andronov-Hopf bifurcation in differential equations with degenerated operator before the derivative

By the methods of branching theory of solutions to nonlinear equations it is investigated the perturbation problem for $n$-multiple pair of pure imaginary eigenvalues at the presence of generalized Jordan chains at Poincaré-Andronov-Hopf bifurcation