Analysis of information sources in references of the Wikipedia article "Al-Muqawqis" in English language version.
[T]he original of the letter was discovered in 1858 by Monsieur Etienne Barthelemy, member of a French expedition, in a monastery in Egypt and is now carefully preserved in Constantinople. Several photographs of the letter have since been published. The first one was published in the well-known Egyptian newspaper Al-Hilal in November 1904.The drawing of the letter published in Al-Hilal was reproduced in David Samuel Margoliouth, Mohammed and the Rise of Islam, London (1905), p. 365, which is the source of this image.
{{cite book}}: ISBN / Date incompatibility (help)[T]he original of the letter was discovered in 1858 by Monsieur Etienne Barthelemy, member of a French expedition, in a monastery in Egypt and is now carefully preserved in Constantinople. Several photographs of the letter have since been published. The first one was published in the well-known Egyptian newspaper Al-Hilal in November 1904.The drawing of the letter published in Al-Hilal was reproduced in David Samuel Margoliouth, Mohammed and the Rise of Islam, London (1905), p. 365, which is the source of this image.