From the reviews of the first edition:

„The book under review is the first systematic and self-contained presentation of a theory of arbitrary order ordinary differential equations with unbounded operator coefficients in a Hilbert or Banach space … . this is an excellent book, that contains recent results of the topic, deep theoretical results and various applications to PDE-s. It is warmly recommended to specialists in ODE-s, PDE-s, functional analysis.“ (Jeno Hegedus, Acta Scientiarum Mathematicarum, Vol. 72, 2006)