1. A rm strong W . D. 1957a Aero. Res. Court. Rep. M emor. no. 2979.
2. 6 Aero;Quart.,1957
3. Bromwich T. J . I 'A. 1949 A n introduction to the theory of infinite series 2nd ed. L ondon: Macmillan.
4. H aw thorne W. R . 1955 Quart. J . Mech. A p p l. M ath. 8 266.
5. H aw thorne W . R . & A rm strong W. D. 1955 Quart. J . Mech. A p p l. M ath. 8 280.