Louisiana Purchase Exposition (1904: St. Louis, Missouri)
MLA
Heller, Alfred E. Louisiana Purchase Exposition (1904: St. Louis, Missouri). 1904. https://collections.library.yale.edu/catalog/2029228.
APA, 6th edition
Heller, A. E. (1904). Louisiana Purchase Exposition (1904: St. Louis, Missouri). https://collections.library.yale.edu/catalog/2029228.