Listed below are additional sources of information:
Iowa Department of Cultural Affairs
Framework of Guidance for Building Good Digital Collections
https://www.imls.gov/publications/framework-guidance-building-good-digital-collections
U.S. National Park Service Conserve O Grams– Collection Care and Conservation Bulletins
https://www.nps.gov/museum/publications/conserveogram/cons_toc.html
Minnesota Historical Society- Care of Shell in Collections
https://www.mnhs.org/preserve/conservation/connectingmn/docs_pdfs/repurposedbook-shell_000.pdf