Williams, D.M. and Vijver, B.V.D. 2023. An electron microscope study and re-description of the type specimens of Synedra subula and its transfer to Ctenophora (Bacillariophyta). Phytotaxa. 629, 2 (Dec. 2023), 176–180. DOI:https://doi.org/10.11646/phytotaxa.629.2.7.