Arguably the most important work on Opiliones ever written. This is a book with more than 1,000 pages, dealing with every single species known at the time. Most impressive of all, the author, Roewer, did not stop at this effort, but went on publishing a score of supplements, each with 50+ pages.
Roewer, C.F. (1923) Die Weberknechte der Erde. Systematische Bearbeitung der bisher bekannten Opiliones. Gustav Fischer, Jena, 1116 pp.