1. The Accotink schist, Lake Barcroft metasandstone, and Popes Head Formation--keys to an understanding of the tectonic evolution of the northern Virginia Piedmont Author/Creator: Drake, Avery Ala, 1927- author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1981 Resource Type: Book Access & Availability: Loading
2. An appraisal of the Great Basin Middle Cambrian trilobites described before 1900 Author/Creator: Palmer, Allison R., author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1954 Resource Type: Book Access & Availability: Loading