Groot, G. E. d. (1963). Rugose corals from the Carboniferous of northern Palencia (Spain). Druk van J.J. Groen.
Lua i Stíl Chicago (17ú heag.)Groot, G. E. de. Rugose Corals from the Carboniferous of Northern Palencia (Spain). Leiden: Druk van J.J. Groen, 1963.
Lua MLA (8ú heag.)Groot, G. E. de. Rugose Corals from the Carboniferous of Northern Palencia (Spain). Druk van J.J. Groen, 1963.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.