Read the following paragraph and determine if the hypothesis is true:

Montasser el-Zayat (] ) or Muntasir al-Zayyat (Arabic: "Muntasir az-Zayyat ") (born 1956) is an Egyptian lawyer and author whose former clients, according to press reports, included Ayman al-Zawahiri, since 2011 the leader of al-Qaeda, the terrorist organization, and al-Gama'a al-Islamiyya.

Hypothesis: Montasser was the author of multiple books.
It's impossible to say