Bacillus aerius sp. nov., Bacillus aerophilus sp. nov., Bacillus stratosphericus sp. nov. and Bacillus altitudinis sp. nov., isolated from cryogenic tubes used for collecting air samples from high altitudes". International Journal of Systematic and Evolutionary Microbiology 56 (7): 1465–1473. doi:10.1099/ijs.0.64029-0. ISSN 1466-5026. PMID 16825614.