Hymenoptera of America north of Mexico : synoptic catalog /
prepared cooperatively by specialists on the various groups of hymenoptera under the direction of C.F.W. Muesebeck, Karl V. Krombein and Henry K. Townes.
- Washington : United States Government Printing Office, 1951.
- 1420 p. : fold. map. ; 24 cm.
- United States. Dept. of Agriculture. Agriculture monograph ; no. 2. .