Feng, H., Zhang, Z., Jia, B., Zuo, Z., Smallbone, A., & Paul Roskilly, A. (2021). Investigation of the optimum operating condition of a dual piston type free piston engine generator during engine cold start-up process. Applied Thermal Engineering, 182, Article 116124. https://doi.org/10.1016/j.applthermaleng.2020.116124