1. Bird, R. B., Stewartson, W. E., and Lightfoot, E. N., Transport Phenomena, 1st ed., Ambrosiana,Milan, 1960, pp.518-523(inItalian).
2. Bird, G. A., Molecular Gas Dynamics and the Direct Simulation of Gas Flows, Clarendon, Oxford, 1998, pp.1-23, 40, 41.