The urbanistic history and quasi-political character of these interrelated civic spaces and structures expressing conflicting connotations of papal and communical-republican instruments of government are discussed in Naomi Miller, Renaissance Bologna: A Study in Architectural Form and Content (University of Kansas) 1989.
Date in Charles Avery, Giambologna (1987); a description of the fountain appears in the second edition (1568) of Giorgio Vasari's Vite; a collection of essays on the conservation undertaken in the 1980s on the Neptune fountain, Il Nettuno del Giambologna: storia e restauro (Milan) 1989, contains an essay by Richard Tittle on the contracts for it, of 1563, and one by Giancarlo Roversi on its impact on public life in Bologna and changing attitudes towards its display of nudity.
