“ULTRASTRUCTURE OF SOME PERMIAN AND TRIASSIC SPIRIFERIDA AND ATHYRIDIDA (BRACHIOPODA)”. RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA 99, no. 3 (September 30, 1993). Accessed July 27, 2026. https://test-ojs-unimi-it.archicoop.it/index.php/RIPS/article/view/8899.