Bulletin - United States National Museum (G.P.O, 1923)

Bulletin - United States National Museum (G.P.O, 1923)

Bulletin of the British Museum (Natural History). Entomology. Supplement - British Museum (Natural History) (BM(NH), 1969)

Bulletin of the British Museum (Natural History). Entomology. Supplement - British Museum (Natural History) (BM(NH), 1969)

Bulletin of the British Museum (Natural History). Entomology. Supplement - British Museum (Natural History) (BM(NH), 1969)

Catalog of hymenoptera in America north of Mexico - Krombein, Karl V. (Smithsonian Institution Press, 1979)

Hymenoptera of America north of Mexico : synoptic catalog - Krombein, Karl V. (U.S. Dept. of Agriculture, 1951)

Hymenoptera of America north of Mexico : synoptic catalog - Krombein, Karl V. (U.S. Dept. of Agriculture, 1951)

Memorie della Società entomologica italiana - Società entomologica italiana. (F.lli Pagano, 1990)