Mármol, G.M.D., Geniez, P., Neumann, A., Glaw, F. and Fritz, U. 2025. Phenotypic variability in the western grass snake Natrix astreptophora, with description of a new subspecies from Morocco. Zootaxa. 5693, 1 (Sep. 2025), 41–65. DOI:https://doi.org/10.11646/zootaxa.5693.1.3.