Fyhn, U.E.H. & Fyhn, H.J. & Davis, B.J. & Powers, D.A. & Fink, W.L. & Garlick, R.L. (1979)
Hemoglobin heterogeneity in Amazonian fishes. Comparative Biochemistry and Physiology – Part A, Physiology, 62(1), 39–66
DOI: 10.1016/0300-9629(79)90740-0

Martin, J.P. & Bonaventura, J. & Fyhn, H.J. & Fyhn, U.E.H. & Garlick, R.L. & Powers, D.A. (1978)
Structural and functional studies of hemoglobins isolated from Amazon stingrays of the genus Potamotrygon. Comparative Biochemistry and Physiology – Part A, Physiology, 62(1), 131–138
DOI: 10.1016/0300-9629(79)90745-X

Martin, J.P. & Bonaventura, J. & Fyhn, H.J. & Fyhn, U.E.H. & Garlick, R.L. & Powers, D.A. (1978)
Estudo da estrutura e função das hemoglobinas isoladas das arraias da Amazônia do gênero Potamotrygon. Acta Amazonica, 8(4), 173–184

Fyhn, U.E.H. & Sullivan, B. (1975)
Elasmobranch hemoglobins: Dimerization and polymerization in various species. Comparative Biochemistry and Physiology – Part B, Comparative Biochemistry, 50(1), 119–129
DOI: 10.1016/0305-0491(75)90311-9