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.