Markus A. Denzel, Handbook of World Exchange Rates, 1590-1914, Ashgate Publishing, 2010, p. 599, ISBN 978-0-7546-0356-6.
«The piastre of 1839 contained 1.146 grammes of fine silver, the piastre of 1801 approximately 4.6 grammes of fine silver. The most important Egyptian coins, the bedidlik in gold (= 100 piastres; 7.487 grammes of fine gold) and the rial in silver (20 piastres; 23.294 grammes of fine silver)»
