Free Library of Philadelphia, Mongan, E., & Wolf, E. (1940). The first printers and their books: A catalogue of an exhibition commemorating the five hundredth anniversary of the invention of printing. The Free library of Philadelphia.
Chicago Style (17th ed.) CitationFree Library of Philadelphia, Elizabeth Mongan, and Edwin Wolf. The First Printers and Their Books: A Catalogue of an Exhibition Commemorating the Five Hundredth Anniversary of the Invention of Printing. [Philadelphia]: The Free library of Philadelphia, 1940.
MLA (8th ed.) CitationFree Library of Philadelphia, et al. The First Printers and Their Books: A Catalogue of an Exhibition Commemorating the Five Hundredth Anniversary of the Invention of Printing. The Free library of Philadelphia, 1940.
Warning: These citations may not always be 100% accurate.