Bulletin : report of Agricultural Experiment Station, Agricultural and Mechanical College, Auburn, Ala - Agricultural; Mechanical College of Alabama. Agricultural Experiment Station. (The Station, 1888)

Bulletin - State Geological and Natural History Survey of Connecticut - State Geological; Natural History Survey of Connecticut. (State Geological and Natural History Survey of Connecticut, 1923)

Bulletin - United States. Bureau of Plant Industry. (G.P.O, 1907)

Bullettino della Società botanica italiana - Società botanica italiana. (Società botanica italiana, 1894)

Bullettino della Società botanica italiana - Società botanica italiana. (Società botanica italiana, 1901)

The Cactaceae : descriptions and illustrations of plants of the cactus family - Britton, Nathaniel Lord, 1859 -1934 (Carnegie Institution of Washington, 1919)

The Cactaceae : descriptions and illustrations of plants of the cactus family - Britton, Nathaniel Lord, 1859 -1934 (Carnegie Institution of Washington, 1920)