1959/12/01 by John Butler, John B. Butler · 1 citation
Mathematics · #Algebra over a field #Differential Equations and Boundary Problems #Eigenvalues and eigenvectors #Mathematical analysis #Mathematics #Numerical methods in inverse problems #Perturbation (astronomy) #Physics #Pure mathematics #Quantum mechanics #Series (stratigraphy) #Spectral Theory in Mathematical Physics
paper · doi:10.1007/bf01240753
openalex publication_date 1959/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23