Phillips, J. 1836. Illustrations of the Geology of Yorkshire; or a Description of the Strata and Organic Remains: accompanied by a geological map, sections and diagrams, and figures of the fossils. Part II. The Mountain Limestone District. 253 pp., 25 pls. https://www.biodiversitylibrary.org/page/53044151.
Phillips, 1836. Illustrations of the Geology of Yorkshire, Part II: 209, 247, pl. 5, fig. 18.