File:Cresson, E. T. 1928. The types of Hymenoptera in the Academy of Natural Sciences of Philadelphia other than those of Ezra T. Cresson. Mem. Am. Entomol. Soc. 5, 1-90.pdf

Cresson, E. T. 1928. The types of Hymenoptera in the Academy of Natural Sciences of Philadelphia other than those of Ezra T. Cresson. Memoirs of the American Entomological Society 5:1-90. [1928-09-14] PDF 123938