MLA
Richter & Co. Art Studio (Philadelphia, Pa.). Portrait of the daughter of Thompson, Poulson. unknown. Robert Langmuir African American Photograph Collection. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/726xwdbrxk-cor.
APA, 6th edition
Richter & Co. Art Studio (Philadelphia, Pa.). (unknown)[Portrait of the daughter of Thompson, Poulson]. Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/726xwdbrxk-cor.
Chicago
Richter & Co. Art Studio (Philadelphia, Pa.), Portrait of the daughter of Thompson, Poulson, unknown, Robert Langmuir African American Photograph Collection, Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/726xwdbrxk-cor.