1. For a comparative analysis of ISO 14001 and ISO 90011, see BlockM.R., Implementing ISO 14001, Milwaukee: ASQC Quality Press books, 1997, pp. 123–133, and Tibor, T. and I. Feldman, ISO 14000: A Guide to the New Environmental Management Standards, Chicago: Irwin, 1996, pp. 203-208. The ISO 14001 also has a comparative diagram describing correspondences between the two systems (annexed).