Journal volume

Robbins, C.B. 1991. Volume 104. Proc. Biol. Soc. Wash.: 10 unno. pp., [1]-893. ≡

Journal issues

1. Robbins, C.B. (ed.), 1991. Number 1, 13 Mar 1991: 1-207.
2. Robbins, C.B. (ed.), 1991. Number 2, 18 Jun 1991: 209-415, 2 unno. pp..
3. Robbins, C.B. (ed.), 1991. Number 3, 25 Sep 1991: 419-649.
4. Robbins, C.B. (ed.), 1991. Number 4, 18 Dec 1991: 651-893.