==References====Further reading==* (editor), "Understanding Late Devonian and Permian–Triassic Biotic and Climatic Events", (Volume 20 in series Developments in Palaeontology and Stratigraphy (2006).
М., 1984* Over, Jess(editor), "Understanding Late Devonian and Permian-Triassic Biotic and Climatic Events", (Volume 20 in series Developments in Palaeontology and Stratigraphy (2006).