Marriott, S. B., Morrissey, L. B., Braddy, S. J., Bennett, J. P., Marriott, S., & Tarrant, P. R. (2004). Fish trails from the Lower Old Red Sandstone of Tredomen Quarry, Powys, southeast Wales. Geological Journal, 39(3-4), 337-358. https://doi.org/10.1002/gj.998