Book: Belden, Louise C. 1980 Marks of American Silversmiths in the Ineson-Bissell Collection. 506 p.
• An illustrated glossary of spoon terms, pp. 467-488Book: Belden, Louise C. 1980 Marks of American Silversmiths in the Ineson-Bissell Collection. 506 p.
• Information on John S. Heald and example mark, p. 221Book: Goldsborough, Jennifer Faulds & Harper, Ann Boyce. 1975 Eighteenth and Nineteenth Century Maryland Silver in the Collection of the Baltimore Museum of Art. 204 p.
• Information on John S. Heald, p. 184