On the generalised eigenvalue method and its relation to Prony and generalised pencil of function methodsM. Fischer, B. Kostrzewa, J. Ostmeyer, K. Ottnad, M. Ueding and C. UrbachEur. Phys. J. A, 56 8 (2020) 206DOI: https://doi.org/10.1140/epja/s10050-020-00205-w