Beyer, Henry G. 1886. A Study of the Structure of Lingula (Glottidia) pyramidata Stimp. (Dall). Studies from the Biological Laboratory (Johns Hopkins University), 3(5): 227-265.
Beyer, Henry G. 1886. "A Study of the Structure of Lingula (Glottidia) pyramidata Stimp. (Dall)." Studies from the Biological Laboratory (Johns Hopkins University), 3, (5) 227–265.