“Compagicrinus Fenestratus, a New Lower Ordovician Inadunate Crinoid from North Greenland”. Rapport Grønlands Geologiske Undersøgelse 91 (December 31, 1979): 71–81. Accessed December 5, 2025. https://geusjournals.org/index.php/rapggu/article/view/7622.