Lücke, Friedrich. Versuch einer vollständigen Einleitung in die Offenbarung Johannis oder Allgemeine Untersuchungen über die apokalyptische Litteratur überhaupt und die Apokalypse des Johannes insbesondere. 2nd ed. Commentar über die Schriften des Evangelisten Johannes, 4:1. Bonn: Eduard Weber, 1852. xviii + 1074 pp.
The classic introduction to Revelation and the apocalyptic literature in general by Friedrich Lücke (see here and here) is now available at Google Books, also for download as a pdf-file.
Book I: The Concept and History of Apocalyptic Literature (pp. 9-342)
Book II: The Johannine Apocalypse. Especially its Literary Characterisation and Canonical Evaluation (pp. 345-1070; look for a separate file at Google Books)