Finan, T. M., O'Brian, M. R., Layzell, D., Vessey, J. K., & Newton, W. E. (2002). Nitrogen fixation: Global perspectives : proceedings of the 13th International Congress on Nitrogen Fixation, Hamilton, Ontario, Canada, 2-7 July 2001. CAB International.

Finan, Turlough M., Mark R. O'Brian, David Layzell, J. Kevin Vessey, and William E. Newton. Nitrogen Fixation: Global Perspectives : Proceedings of the 13th International Congress on Nitrogen Fixation, Hamilton, Ontario, Canada, 2-7 July 2001. UK: CAB International, 2002.

Finan, Turlough M., et al. Nitrogen Fixation: Global Perspectives : Proceedings of the 13th International Congress on Nitrogen Fixation, Hamilton, Ontario, Canada, 2-7 July 2001. CAB International, 2002.