Jelaskan Catatan dari Jam astronomis

Joseph, Needham. (1986). Science and Civilization in China: Volume 4, Physics and Physical Technology, Part 2, Mechanical Engineering. Taipei: Caves Books Ltd.

John North. (2005). God's Clockmaker, Richard of Wallingford and the invention of time. Hambledon and London.

Tor Sørnes. (2008). The Clockmaker Rasmus Sørnes. Borgarsyssel Museum, Sarpsborg, 2003 Norwegian edition, and 2008 English edition (available from the museum).

King, Henry. (1978). Geared to the Stars: the evolution of planetariums, orreries, and astronomical clocks, University of Toronto Press.