Henry Mayhew, London Labour and the London Poor, volume 1 (Electronic Text Center, University of Virginia Library), especially "Chapter 11: THE STREET-SELLERS OF STATIONERY, LITERATURE, AND THE FINE ARTS." [an important documentary on the 19th-century broadside ballad and its sellers]

America Singing: Nineteenth-Century Song Sheets (Library of Congress American Memory) ["4291 song sheets"]

Confederate Broadsides -- Z. Smith Reynolds Library, Wake Forest University ["consists of over 250 examples of poems written by southerners and Confederate sympathizers during the Civil War"]

~Masato