Media type: E-Article Title: Genes at different regulatory levels are required for the ammonia control of nodulation in Rhizobium meliloti Contributor: Dusha, Ilona; Kondorosi, Adam Published: Springer Science and Business Media LLC, 1993 Published in: Molecular and General Genetics MGG, 240 (1993) 3, Seite 435-444 Language: English DOI: 10.1007/bf00280398 ISSN: 0026-8925; 1432-1874 Origination: Footnote: