Shergold, John H. (1991). "Protaspid and early meraspid growth stages of the eodiscoid trilobite Pagetia ocellata Jell, and their implications for classification". Alcheringa: An Australasian Journal of Palaeontology. 15 (1): 65–86. Bibcode:1991Alch...15...65S. doi:10.1080/03115519108619010.
Shergold, John H. (1991). "Protaspid and early meraspid growth stages of the eodiscoid trilobite Pagetia ocellata Jell, and their implications for classification". Alcheringa: An Australasian Journal of Palaeontology. 15 (1): 65–86. Bibcode:1991Alch...15...65S. doi:10.1080/03115519108619010.