Erwin, D. H.; Laflamme, M.; Tweedt, S. M.; Sperling, E. A.; Pisani, D.; Peterson, K. J. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science. 2011, 334: 1091–1097. Bibcode:2011Sci...334.1091E. PMID 22116879. doi:10.1126/science.1206375.
Erwin, D. H.; Laflamme, M.; Tweedt, S. M.; Sperling, E. A.; Pisani, D.; Peterson, K. J. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science. 2011, 334: 1091–1097. Bibcode:2011Sci...334.1091E. PMID 22116879. doi:10.1126/science.1206375.
Erwin, D. H.; Laflamme, M.; Tweedt, S. M.; Sperling, E. A.; Pisani, D.; Peterson, K. J. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science. 2011, 334: 1091–1097. Bibcode:2011Sci...334.1091E. PMID 22116879. doi:10.1126/science.1206375.