Splitting Formulas for the Higher and Lower Energy Levels of the One-Dimensional Schrödinger Operator [Erratum]

In S. Albeverio, S. Yu. Dobrokhotov, and E.  S. Semenov Splitting formulas for the higher and lower energy levels of the one-dimensional Schrödinger operator (Vol. 138, №. 1, January, 2004, pp. 98-106), unfortunately, the paper by S. Yu. Slavyanov (Differ. Equations (1969), 5, №. 2, pp. 313-325) was omitted. In that paper, formula (4) for splitting the lower energy levels was published earlier than in the works cited [3]-[5], [9]. Also, the book in which that formula was also published was omitted: S. Yu. Slavyanov and B. Lay, Special Functions: A Unified Theory Based on an Analysis of Singularities [in Russian], Nevskii Dialekt, St. Petersburg (2002). The authors apologize for this omission.