Smith, W. (1853). Synopsis of British Diatomaceae. John Van Voorst, London 1853., 1: 89 pp., pl. 1-31. page(s): p. 56; pl. 18, fig. 172 b [details]
Kociolek, J.P.; Blanco, S.; Coste, M.; Ector, L.; Liu, Y.; Karthick, B.; Kulikovskiy, M.; Lundholm, N.; Ludwig, T.; Potapova, M.; Rimet, F.; Sabbe, K.; Sala, S.; Sar, E.; Taylor, J.; Van de Vijver, B.; Wetzel, C.E.; Williams, D.M.; Witkowski, A.; Witkowski, J. (2023). DiatomBase. Pinnularia directa var. directa W. Smith, 1853. Accessed through: Nozères, C., Kennedy, M.K. (Eds.) (2023) Canadian Register of Marine Species at: https://www.marinespecies.org/carms/aphia.php?p=taxdetails&id=977537 on 2023-09-27
Nozères, C., Kennedy, M.K. (Eds.) (2023). Canadian Register of Marine Species. Pinnularia directa var. directa W. Smith, 1853. Accessed at: https://marinespecies.org/carms./aphia.php?p=taxdetails&id=977537 on 2023-09-27
original descriptionSmith, W. (1853). Synopsis of British Diatomaceae. John Van Voorst, London 1853., 1: 89 pp., pl. 1-31. page(s): p. 56; pl. 18, fig. 172 b [details]