Cite

Gruppenbegriff, Address to the Philosophy Club on [Einleitung am Morgen des 13. April 1945 geschreiben (Cassirer's death date)]: draft, holograph, corrected (Envelope #214)

MLA

Cassirer, Ernst, 1874-1945. Gruppenbegriff, Address to the Philosophy Club on [Einleitung am Morgen des 13. April 1945 geschreiben (Cassirer's death date)]: draft, holograph, corrected (Envelope #214). Box 41, folder 823. 1945 Apr. https://collections.library.yale.edu/catalog/17280104.

APA, 6th edition

Cassirer, Ernst, 1874-1945. (["Box 41, folder 823"])(1945 Apr)[Gruppenbegriff, Address to the Philosophy Club on [Einleitung am Morgen des 13. April 1945 geschreiben (Cassirer's death date)]: draft, holograph, corrected (Envelope #214)]. https://collections.library.yale.edu/catalog/17280104.