Harmony Hall -- U. S. Department of the Interior, Historic American Buildings Survey, survey number 10-8: Harmony Hall, Prince George's County, MD. Scale 1/8"=1'0; 6 sheets; blue line prints with penciled notes. -- Sections, details and half-plan, 1934

Harmony Hall -- U. S. Department of the Interior, Historic American Buildings Survey, survey number 10-8: Harmony Hall, Prince George's County, MD. Scale 1/8"=1'0; 6 sheets; blue line prints with penciled notes. -- Sections, details and half-plan, 1934, 6.2.4, Oversize file: 11, item: 4. Charles Wallace Collins papers, 0022-MDHC. Special Collections and University Archives. https://archives.lib.umd.edu//repositories/2/archival_objects/233597 Accessed November 25, 2024.