– “The Saga of a Japanese Brand of Telescopes Polarex – Unitron – Nihon Seiko”, Anamorfose Curiosa & Arcturus Observatory, Xavier Debeerst, October 13, 2013; Xavier Debeerst Post
– “Unitron Polarex”, Company Seven, http://www.company7.com/library/unitron/notes.html
– “Unitron Refractor Telescopes”, John Siple, Rose City Astronomer Newsletter, January 2003; page 6; http://www.rosecityastronomers.org/news/2003.pdf