Horan, J. D. (1966). Timothy O'Sullivan, America's forgotten photographer: The life and work of the brilliant photographer whose camera recorded the American scene from the battlefields of the Civil War to the frontiers of the West ([1st ed.].). Doubleday.

Horan, James D. Timothy O'Sullivan, America's Forgotten Photographer: The Life and Work of the Brilliant Photographer Whose Camera Recorded the American Scene from the Battlefields of the Civil War to the Frontiers of the West. [1st ed.]. Garden City, N.Y.: Doubleday, 1966.

Horan, James D. Timothy O'Sullivan, America's Forgotten Photographer: The Life and Work of the Brilliant Photographer Whose Camera Recorded the American Scene from the Battlefields of the Civil War to the Frontiers of the West. [1st ed.]. Doubleday, 1966.