Lathrop, Don Haven. «Why is clockwise Clockwise?». Workshop Hints. Donn Haven Lathrop, 2008 (originally British Horological Institute). Arxivat de l'original el 2011-11-15. [Consulta: 27 juny 2008].
Lathrop, Don Haven. «Why is clockwise Clockwise?». Workshop Hints. Donn Haven Lathrop, 2008 (originally British Horological Institute). Arxivat de l'original el 2011-11-15. [Consulta: 27 juny 2008].