Other "species" classified as Spirillum such as "Spirillum minus", "Spirillum pleomorphum", and "Spirillum pulli" are of uncertain phylogeny and in any case, these are names that have never been validly or effectively published and thus have no standing in nomenclature.[1][5]
^ abGarrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual of Systematic Bacteriology, Volume Two: The Proteobacteria, Part C: The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. New York, New York: Springer. pp. 354–361. ISBN978-0-387-24145-6.
^Podkopaeva (D.), Grabovich (M.), Kuever (J.), Lysenko (A.M.), Tourova (T.P.), Kolganova (T.V.) and Dubinia (G.): Proposal of Spirillum winogradskyi sp. nov., a novel microaerophilic species, an amended description of the genus Spirillum and Request for an Opinion regarding the status of the species Spirillum volutans Ehrenberg 1832. Int. J. Syst. Evol. Microbiol., 2009, 59, 2916-2920.
^Krieg, Noel (2006). "Chapter 3.2.5: The Genus Spirillum". In Dworkin, Martin; Falkow, Stanley; Rosenberg, Eugene; Schleifer, Karl-Heinz; Stackebrandt, Erko (eds.). The Prokaryotes: A Handbook on the Biology of Bacteria, Volume 5. Berlin: Springer Science & Business Media. ISBN9780387254951.