Gerd Puin was the head of a restoration project, commissioned by the Yemeni government, which spent a significant amount of time examining the ancient Qur'anic manuscripts discovered in Sana'a, Yemen, in 1972. According to writer Toby Lester, his examination revealed "unconventional verse orderings, minor textual variations, and rare styles of orthography and artistic embellishment." The scriptures were written in the early Hijazi Arabic script, matching the pieces of the earliest Qur'ans known to exist. The papyrus on which some of the text appears shows clear signs of earlier use, being that previous, scraped-off writings are also visible on it, though this does not necessarily demonstrate modifications to the over-all text of the Qur'an.
More than 15,000 sheets of the Yemeni Qur'ans have painstakingly been cleaned, treated, sorted, and photographed and 35,000 microfilmed photos have been made of the manuscripts. Some of Puin's initial remarks on his findings are found in his essay titled the "Observations on Early Qur'an Manuscripts in San'a" which has been republished in the book What the Koran Really Says by Ibn Warraq.