George Wood Vinal: Storage batteries: a general treatise on the physics and chemistry of secondary batteries and their engineering applications. Wiley, Dezember 1955 (google.de [abgerufen am 12. Januar 2012]).
InfoWorld Media Group, Inc.: InfoWorld. InfoWorld Media Group, Inc., 28. August 1989, ISSN0199-6649, S.29 (google.de [abgerufen am 12. Januar 2012]).