W. J. Pettee, grower of the world's finest delphinium in the land of Hiawatha - W. J. Pettee (Firm); Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Marquette, Michigan, W.J. Pettee, [1931], 1931)
https://www.biodiversitylibrary.org/bibliography/152230
Keywords: Bulbs (Plants)|Catalogs|Delphinium|Marquette|Michigan|Nurseries (Horticulture)|Nursery stock|Roots|