* {{cite book | last=Boone | first=David R. | last2=Castenholz | first2=Richard W. | last3=Garrity | first3=George M. | last4=Brenner | first4=Don J. | last5=Krieg | first5=Noel R. | last6=Staley | first6=James T. | title=Bergey's ManualĀ® of Systematic Bacteriology | publisher=Springer Science & Business Media | publication-place=New York | date=2001 | isbn=0-387-24145-0}}
<ref name="b612">{{cite book | last=Boone | first=David R. | last2=Castenholz | first2=Richard W. | last3=Garrity | first3=George M. | last4=Brenner | first4=Don J. | last5=Krieg | first5=Noel R. | last6=Staley | first6=James T. | title=Bergey's ManualĀ® of Systematic Bacteriology | publisher=Springer Science & Business Media | publication-place=New York | date=2001 | isbn=0-387-24145-0 | page=}}</ref>