SCHAAFF, Holger. Antike Tuffbergwerke am Laacher See-Vulkan. Heidelberg: Propylaeum,2021. DOI: 10.11588/propylaeum.861. Disponível em: https://books.ub.uni-heidelberg.de/propylaeum/catalog/book/861.. Acesso em: 28 apr. 2024.