Four-toed Salamander (Hemidactylium scutatum: Jordan, David Starr. 1876. Manual of the Vertebrates of the Northern United States: Including the District East of the Mississippi River, and North of North Carolina and Tennessee, Exclusive of Marine Species. Jansen, McClurg, and Company, Chicago, Illinois.. 342pp.); Four-toed Salamander (Hemidactylium scutatum: Jordan, David S. 1878. Manual of the Vertebrates of the Northern United States: Including the District East of the Mississippi River, and North of North Carolina and Tennessee, Exclusive of Marine Species. Second Edition, Revised, and Enlarged. Jansen, McClurg & Company, Chicago. pp.); Scaly Lizard (Hemidactylium scutatum: Yarrow, Henry C. 1882. Check list of North American Reptilia and Batrachia with catalogue of specimens in U. S. National Museum. Bulletin of the United States National Museum (24):1-249); Four-toed Salamander (Hemidactylium scutatum: Garman, H. 1892. A synopsis of the reptiles and amphibians of Illinois. Illinois Laboratory of Natural History Bulletin 3():215-403); Four-toed Salamander (Hemidactylium scutatum: Hay, Oliver P. 1892. Batrachians and Reptiles of the State of Indiana. Pages 409-624 in 17th Annual Report of the Indiana Department of Geology and Natural Resources, William B. Burford, Printer and Binder, Indianapolis, Indiana. pp.); Scaly Salamander (Hemidactylium scutatum: Hay, Oliver P. 1892. Batrachians and Reptiles of the State of Indiana. Pages 409-624 in 17th Annual Report of the Indiana Department of Geology and Natural Resources, William B. Burford, Printer and Binder, Indianapolis, Indiana. pp.); Four Toed Salamander (Hemidactylium scutatum: Fowler, Henry W. 1907. The amphibians and reptiles of New Jersey. MacCrellish and Quigley, Trenton, N. J.. 29-250pp.); Scaly Salamander (Hemidactylium scutatum: Hurter, Julius. 1911. Herpetology of Missouri. Transactions of the Academy of Science St. Louis 20(5):59-274); Eastern Four-toed Salamander (Hemidactylium scutatum: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.);