1) Sources detailing Al-Kashi's (1424) calculation of pi (using a
regular polygon having 805, 306, 368 sides) which was correct to
16 places of decimals.
2) John L Berggren's e-mail address (who has been involved in the
history of Islamic mathematics).
Many thanks.
Dennis Almeida,
Lecturer in Mathematics Education,
University of Exeter,
Heavitree Road,
Exeter EX1 2LU