Analysis of information sources in references of the Wikipedia article "Manuskrip Sana'a" in Indonesian language version.
Among the manuscripts... discovered in 1972... of the Great Mosque of Sanaa in Yemen was a rare Qur’anic palimpsest – that is, a manuscript preserving an original Qur’an text that had been erased and written over with a new Qur’an text. This palimpsest has been analysed by... Gerd and Elisabeth Puin, by Asma Hilali of the Institute of Ismaili Studies in London, and later by Behnam Sadeghi of Stanford University... What all of these scholars have discovered is remarkable: the earlier text of the Qur’an contains numerous variants to the standard consonantal text of the Qur’an.