Williams, H. S. (1913). Recurrent tropidoleptus zones of the upper Devonian in New York. Govt. Print. Off..
Chicago Style (17th ed.) CitationWilliams, Henry Shaler. Recurrent Tropidoleptus Zones of the Upper Devonian in New York. Washington: Govt. Print. Off., 1913.
MLA (8th ed.) CitationWilliams, Henry Shaler. Recurrent Tropidoleptus Zones of the Upper Devonian in New York. Govt. Print. Off., 1913.
Warning: These citations may not always be 100% accurate.