1. Nassauer S (2017) Wal-Mart, Amazon rivalry spreads to forklifts. Wall Street Journal, July 21, 2017. https://www.wsj.com/articles/wal-mart-amazon-rivalry-spreads-to-forklifts-1500634801
2. Fuel Cell Industry Review (2016). www.FuelCellIndustryReview.com
3. Barbir F (2005) PEM fuel cells. Elsevier, Amsterdam/Boston
4. Srinivasan S (2006) Fuel cells: from fundamentals to applications. Springer, New York
5. Vielstich W, Lamm A, Gasteiger HA (eds) (2003) Handbook of fuel cells. Wiley, Chichester