To find and get books beyond Harvard:
Arabic Discovery Catalog: The Arabic Discovery Catalog is one of the most comprehensive bibliographic databases of Arabic culture. It currently holds more than 1.4 million records in Arabic and more than 2.8 million records containing Arabic script and continues to grow. The search box supports searches in Arabic script and delivers precise search results in an Arabic interface. If you are looking for a resource from an Arabic country, in Arabic script, or related to Arabic culture, you are in the right place. You can filter for printed works as well as all types of electronic resources, and open-access content too.
Borrow Direct: Borrow Direct lets Harvard University researchers with library borrowing privileges and active e-mail accounts find and borrow books directly from the libraries of Brown, University of Chicago, Columbia, Cornell, Dartmouth, Duke, Johns Hopkins, MIT, University of Pennsylvania, Princeton, and Yale. The link takes you to the Borrow Direct online system and you'll be asked to enter your Harvard Key.
Center for Research Libraries: The Middle East Materials Project (MEMP): collections in digital and microform format of unique, rare, hard to obtain, and often expensive research material for Middle East studies; for detailed information about the collections follow this link
Gallica, La Bibliothèque Nationale de France: Digital collections of books and images in the French National Library.
Gazi Husrev-bey Library, The Gazi-Husrev-beg Library is a public library in Sarajevo, Bosnia and Herzegovina founded in 1537, and is part of a larger complex with Gazi Husrev-beg Medresa. It holds one of the most important collections of Islamic manuscripts in Bosnia-Herzegovina, including many originally donated by Gazi Husrev-beg. The collection survived through Bosnian war and Siege of Sarajevo. The library also holds a sizable number of books, journals, newspapers, documents and photographs. (wikipedia_ https://en.wikipedia.org/wiki/Gazi_Husrev-beg_Library). Harvard Library has volumes 1-18 of the Catalogue of the Arabic, Turkish, Persian & Bosnian manuscripts in the Ghazi Husrev-Bey Library, Sarajevo. (Hollis Record - Here)
Google Books: lets you search the full text of all books available in Google Book Search with a Find at Harvard University link displayed on every item in a search result set. Clicking the link brings the user to the catalog record if an exact match is found in HOLLIS. If an electronic version of the book has been licensed by Harvard, the user will be taken directly to the full text of the e-book. If an exact match in HOLLIS is not found, a pre-populated HOLLIS search screen will open making it easy for patrons to launch a HOLLIS search session.
Hathi Trust: a shared repository of works digitized by more than 50 research library members across the United States, Canada, and Europe. As of 2015 HathiTrust comprised over 13.7 million volumes, including 5.3 million of which were in the public domain in the U.S. Public domain titles may be viewed in full text
al-Maktabah al-Waqfiyah: e-books available through the Internet Archive
Middle East in Microform: a Union list of Middle Eastern Microforms in North American libraries
The Qatar Digital Library: a vast archive featuring the cultural and historical heritage of the Gulf and wider region freely available online, it includes archives, maps, manuscripts, sound recordings, photographs and more, with explanatory notes and links, in both English and Arabic. Developed through a partnership among the Qatar Foundation, the Qatar National Library and The British Library
Shamela Library (al-Maktabah al-Shāmilah): a large (6,000 volumes+), free digital collection of Arabic books online, useful to researchers studying pre-modern Middle Eastern history or modern Islamic thought
ULB Sachsen-Anhalt Middle East and North Africa Special Area Collection – Digital: the University and State Library Saxony-Anhalt in Halle (ULB Halle) has digitized over 3050 volumes of Titles belonging to the Middle East and North Africa Special Area Collection (Sondersammelgebiet 6.23); the selected titles for digitization are free of copyright restrictions. They belong to the old holdings of the Library of the German Oriental Society (Deutsche Morgenländische Gesellschaft). A part of the selected titles are more recent publications that are digitized with special permissions of the publishers.
University of Cambridge Online Manuscript Collections and Catalogues: the Near and Middle Eastern manuscripts collection covers a wide range of texts in Arabic (over 2500 codices), Hebrew (over 1000), Persian (over 1200), Syriac (around 300) and Turkish (around 450). There are also smaller collections in Coptic, Ethiopic, Armenian, Malay, Urdu and languages of Ancient Egypt.
WorldCat (FirstSearch) and the Karlsruhe Virtual Catalog (KVK) are large online catalogs in which you can search simultaneously the holdings of many major libraries (WorldCat is mainly for US/Canadian libraries, while Karlsruhe Virtual Catalog searches libraries in Germany, Austria, Switzerland, France, Spain, and the UK).