Patterson, Richard Sharpe; Dougall, Richardson (1978) [1976 i.e. 1978]. The Eagle and the Shield: A History of the Great Seal of the United States. Department and Foreign Service series; 161 Department of State publication; 8900. Washington : Office of the Historian, Bureau of Public Affairs, Dept. of State : for sale by the Supt. of Docs., U.S. Govt. Print. Off. pp. 111–121. LCCN78602518. OCLC4268298.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Stanton, Virginia: American History Press. pp. 5–12. ISBN978-1-939995-09-4. LCCN2015931682.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Staunton, Virginia: American History Press. pp. 13–27. ISBN978-1-939995-09-4. LCCN2015931682.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Staunton, Virginia: American History Press. pp. 29–66. ISBN978-1-939995-09-4. LCCN2015931682.
Patterson, Richard Sharpe; Dougall, Richardson (1978) [1976 i.e. 1978]. The Eagle and the Shield: A History of the Great Seal of the United States. Department and Foreign Service series; 161 Department of State publication; 8900. Washington : Office of the Historian, Bureau of Public Affairs, Dept. of State : for sale by the Supt. of Docs., U.S. Govt. Print. Off. pp. 111–121. LCCN78602518. OCLC4268298.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Staunton, Virginia: American History Press. pp. 41–56. ISBN978-1-939995-09-4. LCCN2015931682.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Staunton, Virginia: American History Press. pp. 67–91. ISBN978-1-939995-09-4. LCCN2015931682.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Staunton, Virginia: American History Press. pp. 95–155. ISBN978-1-939995-09-4. LCCN2015931682.
Nyberg, William (2015). Robert Scot: Engraving Liberty. Staunton, Virginia: American History Press. pp. 135–143. ISBN978-1-939995-09-4. LCCN2015931682.
Patterson, Richard Sharpe; Dougall, Richardson (1978) [1976 i.e. 1978]. The Eagle and the Shield: A History of the Great Seal of the United States. Department and Foreign Service series; 161 Department of State publication; 8900. Washington : Office of the Historian, Bureau of Public Affairs, Dept. of State : for sale by the Supt. of Docs., U.S. Govt. Print. Off. pp. 111–121. LCCN78602518. OCLC4268298.