T. B. Hughes: A Dictionary of Islam. London, 1896. Very full of information, but to be used with caution. Based on Persian sources largely.
E. W. Lane: An Account of the Manners and Customs of the Modern Egyptians. First edition, London, 1836; third, 1842. Many others. Indispensable.
C. M. Doughty: Travels in Arabia Deserta. 2 vols. Cambridge, 1888. By far the best book on nomad life in Arabia. Gives the fullest and clearest idea of the nature and workings of the Arab mind.
J. L. Burckhardt: Notes on the Bedouins and Wahabys. 2 vols. London, 1831.
J. L. Burckhardt: Travels in Arabia. 2 vols. London, 1829.
R. F. Burton: Personal Narrative of a Pilgrimage to al-Madinah and Meccah. 2 vols. Last edition, London, 1898. On the Hajj and Muslim life, thought and studies generally in the middle of the nineteenth century. Readable and accurate to a degree.
C. Snouck Hurgronje: Mekka. 2 vols. and portfolio of plates. Haag, 1888, 1889. Is somewhat dull beside Burton, but very full and accurate.
W. Robertson Smith: Lectures on the Religion of the Semites. First Series. New edition, London, 1894. Kinship and Marriage in Early Arabia. Cambridge, 1885.
Ignaz Goldziher: Muhammedanische Studien. I, Halle a. S., 1889. II, 1890. Epoch-marking books; as are all Goldziher’s contributions to the history of Muslim civilization.