by Jan Larue, Eugene K. Wolf, Mark Evan Bonds, Stephen Walsh and Charles Wilson. An extensive article organized into sections based on the century and geographic location. Includes an excellent bibliography. You might also want to read the "Orchestra" entry in this same resource.
2013. by Nicolas Waldvogel. An excellent annotated bibliography with General Overviews, Shorter Surveys, Dictionaries, and sections on The 18th Century, Ludwig van Beethoven, The 19th Century, Gustav Mahler, and The 20th Century.
2012. by A. Peter Brown. "Central to the repertoire of Western art music since the 18th century, the symphony has come to be regarded as one of the ultimate compositional challenges. In his five-volume series The Symphonic Repertoire, the late A. Peter Brown explores: v. 1. The eighteenth-century symphony -- v.2. The first golden age of the Viennese symphony: Haydn, Mozart, Beethoven, and Schubert -- v. 3A. The European symphony, ca. 1800-ca. 1930: Germany and the Nordic countries -- v. 3B. The European symphony, ca. 1800-ca. 1930: Great Britain, Russia, and France -- v.4. The second golden age of the Viennese symphony: Brahms, Bruckner, Dvorak, Mahler, and selected contemporaries -- v. 5. The symphony in Europe and the Americas in the twentieth century."