For a considerable time, Ibadism was a neglected research object, both in the West, as well as in the Arab world and beyond. However, this has changed rapidly for about a decade. More and more students, researchers and scientists are paying attention to Ibadism and its rich history in the Maghreb, Mashriq and the Indian Ocean region, especially in Zanzibar and East Africa. International conferences with all aspects of the al-Ibadiyya, which are often encouraged by the Omani Ministry of Foundations and Religious Affairs, are becoming a recurring phenomenon. The Ibadites are no longer equated with the Kharijis and the negative connotations associated with this movement. Further studies might even lead to the understanding that al-Ibadiyya can be regarded as the oldest of all Islamic Madhahibs. The three volumes Al-Ibadiyya, a Bibliography offer a comfortable tool in the study of Ibadism. The first two volumes Ibadis of the Mashriq and Ibadis of the Maghrib, including Egypt, contain works by Ibadi authors, including ready-to-print works and manuscripts, which mainly belong to the Ibadi Turath. In addition to information on the authors and their works, there are secondary sources and references to related elements in the other two volumes; Details of the manuscripts are given together with their locations. A name index makes it easy to find a specific author. The third volume of this bibliography, the secondary literary literature, is to be attributed not only to publications which are directly and exclusively due to Ibadism books, articles, dissertations, and unpublished lectures; titles which often have an indirect connection with Ibadism, such as Ibadi-related themes of Djerba, Jabal Nafusa, Mizab, the modern history of Oman, Zanzibar, etc. These are complemented by numerous cross-references and related elements within this volume as well as the other two volumes. Selected subject registers at the end facilitate the targeted search. The three volumes of this second, revised and expanded edition of the Al-Ibadiyya bibliography are the result of travels to Mizab, Djerba, Tripolitania and Cairo in the early 1970s, also recent sections based on the work of a total of six months in the various well-equipped libraries of the Sultanate of Oman, as well as studying as many publications as possible on Ibadism and not least the extensive research on the Internet. Al-Ibadiyya, a Bibliography should therefore be regarded as a handbook on Ibadism, as a mere bibliography. Beginners of studies, as well as experienced researchers will find in these volumes an indispensable tool for their studies.