Delabre, Christiane; et al. (2002). "Complete Mitochondrial DNA of the Hagfish, Eptatretus burgeri: The Comparative Analysis of Mitochondrial DNA Sequences Strongly Supports the Cyclostome Monophyly". Molecular Phylogenetics and Evolution. 22 (2): 184–192. doi:10.1006/mpev.2001.1045. PMID11820840.
Stock, David; Whitt GS (7 באוגוסט 1992). "Evidence from 18S ribosomal RNA sequences that lampreys and hagfishes form a natural group". Science. 257 (5071): 787–9. doi:10.1126/science.1496398. PMID1496398. {{cite journal}}: (עזרה)
nih.gov
pubmed.ncbi.nlm.nih.gov
Delabre, Christiane; et al. (2002). "Complete Mitochondrial DNA of the Hagfish, Eptatretus burgeri: The Comparative Analysis of Mitochondrial DNA Sequences Strongly Supports the Cyclostome Monophyly". Molecular Phylogenetics and Evolution. 22 (2): 184–192. doi:10.1006/mpev.2001.1045. PMID11820840.
Stock, David; Whitt GS (7 באוגוסט 1992). "Evidence from 18S ribosomal RNA sequences that lampreys and hagfishes form a natural group". Science. 257 (5071): 787–9. doi:10.1126/science.1496398. PMID1496398. {{cite journal}}: (עזרה)