M. I.  Romero, Amigo, J., and Ramil, P., ?Isoetes fluitans sp. nov.: The identity of Spanish plants of 'I. longissimum'?, Botanical Journal of the Linnean Society, vol. 146, no. 2, pp. 231 - 236, 2004.

M. I.  Romero and Real, C., ?A morphometric study of three closely related taxa in the European Isoetes velata complex?, Botanical Journal of the Linnean Society, vol. 148, no. 4, pp. 459 - 464, 2005.