Media type: E-Article Title: The Occurrence of Singularities in the Elastic Frequency Distribution of a Crystal Contributor: Van Hove, Léon Published: American Physical Society (APS), 1953 Published in: Physical Review, 89 (1953) 6, Seite 1189-1193 Language: English DOI: 10.1103/physrev.89.1189 ISSN: 0031-899X Origination: Footnote: