Fontaine, M S Effects of long-term preservation of frankia strains on infectivity, effectivity, and in vitro nitrogenase activity. [electronic resource] - Applied and environmental microbiology Apr 1986 - 694-8 p. digital Publication Type: Journal Article ISSN: 0099-2240 Standard No.: 10.1128/aem.51.4.694-698.1986 doi