Georg Fleming Richardson, Geology for beginners, Londres, Longman, Brown, Green & Longmans, 1843, p.439-440.
Archives du mot-clé fossil
Composed of clay
Beck, « Notes on the Geology of Denmark (Beck) », Proceedings of the Geological Society of London, Londres, vol. 2, n° 43, 1835.
It is unnecessary
Charles Lyell, Principles of Geology, vol. III, Londres, John Murray, 1830, p. 232-233.
We remember
Anonyme, The Mirror of Literature, Amusement and Instruction, vol X. n° 284, samedi 24 novembre, Londres, 1827.