Fox G E, Stackebrandt E, Hespell R B, Gibson J, Maniloff J, Dyer T A, Wolfe R S, Balch W E, Tanner R S, Magrum L J, Zablen L B, Blakemore R, Gupta R, Bonen L, Lewis B J, Stahl D A, Luehrsen K R, Chen K N, Woese C R
Science. 1980 Jul 25;209(4455):457-63. doi: 10.1126/science.6771870.