Williams, D. M., P. A. Sims, and M. P. Ashworth. “Notes on the Diatom Collection of the Natural History Museum, London (BM) X: Roper’s Species of Biddulphia (Bacillariophyta)”. Phytotaxa, vol. 755, no. 2, May 2026, pp. 121-53, doi:10.11646/phytotaxa.755.2.1.