1. Purday, H. F. P., Streamline flow, Constable, London 1949.
2. Prins, J. A., J. Mulder and J. Schenk, Appl. sci. Res.A2 (1950) 431.
3. Does de Bye, J. A. W. van der and J. Schenk, Appl. sci. Res.A3 (1952) 308.
4. Mulder, J., private communication.
5. See for this solution e.g. M. Jakob, Heat transfer, London-New York 1949.