Reference: Hatcher, J. B. , O. C. Marsh , and R. S. Lull . 1907. The Ceratopsia. U.S. Geological Survey Monograph 49, 300 p This monograph has been scanned as five separate PDFs: Intro & Contents Part 1 -monograph Part 2 Plates Index (previewed on right) You will need all five to have the complete article. Article scanned as part of the Dinosaur Digital Library Project, a for-research-only resource since 2004. This PDF is fully text searchable. Text and line drawings are scanned at 300dpi, plates at 600 dpi. This allows you to see each individual ink dot for faithful reproduction when printing for research. Clicking "The dinosaur digital library project" under the publisher link should bring up other titles that have been uploaded as part of the project. This scan by D. W. Fowler.