1. Development of hybrid railcars and catenary and battery-powered hybrid railcar system;Abiko;JR East Technical Review,2012
2. The development of low floor battery-driven LRV SWIMO;Akiyama,2008
3. East Japan Railway Company, (2014). Accumulator system (ACCUM). JR East Group CSR report (p. 47).
4. Catenary-free trams: Technology and recent developments;Global Mass Transit,2014
5. Saft providing NiMH batteries to Alstom and Lohr for hybrid tram applications;Green Car Congress,2005