The fishes of the west coast of Peru and the Titicaca Basin. Bulletin of the United States National Museum, 95, 1–166
Studies on the head in fishes. Embryological, morphological, and phylogenetical researches. Part I. Development of the skull in sharks and rays. Acta Zoologica(Stockholm), 21(1–3), 51–267
DOI: 10.1111/j.1463-6395.1940.tb00339.x