«MORPHOLOGICAL VARIATION IN HEMIGORDIUS HARLTONI CUSHMAN &AMP; WATERS, 1928: REMARKS ON THE TAXONOMY OF CARBONIFEROUSAND PERMIAN HEMIGORDIOPSIDS». 2003. Rivista italiana di Paleontologia e Stratigrafia 109 (2). https://doi.org/10.13130/2039-4942/5502.