Perez, K.E., Leal, M.S., Glover, H., Chastain, R.T., Hutchins, B.T. & Schwartz, B. (2021)

Two new species of Pyrgulopsis Call & Pilsbry, 1886 (Mollusca: Caenogastropoda: Hydrobiidae) from springs in the Rio Grande watershed in Texas

. Zootaxa, 5071 (3), 384–402.