Proceedings of the Biological Society of Washington.

v. 12 (1898)

Proceedings of the Biological Society of Washington.

v. 11 (1897)

Catalog of hymenoptera in America north of Mexico / prepared cooperatively by specialists on the various groups of Hymenoptera under the direction of Karl V. Krombein ... [et al.].

vol. 1

Catalog of hymenoptera in America north of Mexico / prepared cooperatively by specialists on the various groups of Hymenoptera under the direction of Karl V. Krombein ... [et al.].

vol. 3

Catalog of hymenoptera in America north of Mexico / prepared cooperatively by specialists on the various groups of Hymenoptera under the direction of Karl V. Krombein ... [et al.].

vol. 2