SDR papers
The SDR nomenclature system is described in the article:
Bengt Persson, Yvonne Kallberg, James E. Bray, Elspeth Bruford, Stephen L. Dellaporta, Angelo D. Favia, Roser Gonzalez Duarte, Hans Jörnvall, Kathryn L. Kavanagh, Natalia Kedishvili, Michael Kisiela, Edmund Maser, Rebekka Mindnich, Sandra Orchard, Trevor M. Penning, Janet M. Thornton, Jerzy Adamski and Udo Oppermann
The SDR HMM family classification system is described in the article:
Yvonne Kallberg, Udo Oppermann and Bengt Persson