Native Bees, Wild Bees and Solitary Bees: University of Minnesota
Nesting Blocks and Bee Condos, UC Berekley Urban Bee Lab
Nests for Native Bees: The Xerces Society
Stem-nesting Bees, How to Create Habitat (infographic), Heather Holm
Tunnel Nests for Native Bees: The Xerces Society