1. Komatsu Introduces the World’s First Hydraulic Excavator: Hybrid Evolution Plan for Construction Equipmenthttp://www.komatsu.com/CompanyInfo/press/2008051315113604588.html
2. 336E H Hybrid, Benefits and Featureshttp://www.cat.com/en_US/products/new/equipment/excavators/large-excavators/18378156.html
3. Development of new hybrid excavator;Kagoshima;Kobelco Technol. Rev.,2007