New Horizons in Nitrogen Fixation : proceedings of the 9th international congress on nitrogen fixation, Cancun, Mexico, December 6-12, 1992 / edited by Rafael Palacios, Jaime Mora and William E. Newton Palacios, Rafael Mora, Jaime Newton, William E. Nitrogen -- Fixation. Plant-microbe relationships -- Congresses. 589.95 355541 Includes bibliographical references and index. London : Kluwer Academic Publishers, c1993. c1993. 1993 Text xvi, 788 p. : eng