^ ابKirchhof G; Eckert B; Stoffels M; Baldani JI; Reis VM; Hartmann A (1 Jan 2001). "Herbaspirillum frisingense sp. nov., a new nitrogen-fixing bacterial species that occurs in C4-fibre plants". International Journal of Systematic and Evolutionary Microbiology (بالإنجليزية). 51 (1): 157–168. DOI:10.1099/00207713-51-1-157. ISSN:1466-5026. PMID:11211253. QID:Q30633121.