1. Ucarol H, Kaypmaz A, Tuncay RN, Tur O (2005) A performance comparison study among conventional, series hybrid and parallel hybrid vehicles. http://www.emo.org.tr/ekler/c792a8279211dec_ek.pdf
2. Caterpillar. http://catsays.blogspot.com/2005/01/caterpillar-797b-mining-truck.html
3. Komatsu product brochure.. https://www.komatsuamerica.com/equipment/trucks/electric/980e-4
4. Wikimedia. http://commons.wikimedia.org/wiki/File:Liebherr_T282.jpg. (Also see Liebherr product brochure, http://www.liebherr.com/ME/en-GB/products_me.wfw/id-14270-0)
5. Komatsu technical report. https://home.komatsu/en/company/tech-innovation/report/pdf/166-E05.pdf