Bibliographical references Beard, R. E. (1971): 0n the calculation of the ruin probability for a finite time period. ASTIN bulletin. Dec. 1971. Vol. VI. Part. 2. Pgs 129-133. Beard, R. E.; Pentikäinen, T and Pesonen, E (1984): Risk Theory. Chapman and Hall publishers. New York. Pgs 227-233. Bühlmann, H (1970): Mathematical methods in risk theory. Springer-Verlag, Berlin. Pgs. 137-139. De Vylder, F and Goovaerts, M. J. (1988): Recursive calculation of finite time ruin probabilities. Insurance: mathematics and economics; 7. 1988; pgs 93-97. Wikstad, N (1971): Exemplification of ruin probabilities. ASTIN bulletin 6; pgs 147-152.