Alexander Marx was an American historian, bibliographer and librarian. Wikipedia
Books
Essays in Jewish Biography
1947
A Seventeenth-century Autobiography
1918
Studies in Jewish History and Booklore
1944
Hebrew Incunabula
1920
Bibliographical Studies and Notes on Rare Books and Manuscripts in the Library of the Jewish Theological Seminary of America
The Mayer Sulzberger, Alexander Marx Correspondence, 1904-1923