Klapwijk, P.M., Hooykaas, P.J.J., Kester, H.C.M., Schipperoort, R.A., Rörsch, A. 1976. Isolation and characterization of Agrobacterium tumefaciens mutants affected in the utilization of octopine, octopinic acid and lysopine. Journal of General Microbiology. 96 : 155-163.