1. Article 5 – No title. The New York Times (25 May 1880).
2. Bell, T. (1986). In the shadow of giants: Forgotten nineteenth century American telescope makers and their crucial role in popular astronomy. Griffith Observer, 50(9), 3–14.
3. Berendzen, R. (1977). Origins of the American Astronomical Society. Physics Today, 27(12), 32–39.
4. Birth and growth of the Solar System. The New York Times, 23 January 1874.
5. Boston Scientific Society. (1886). The Science Observer V2–5, 1878–1886: A journal for scientists. Boston: Boston Scientific Society.