1. 1) Varnes, D. J. and IAEG Commission on Landslides : Land-slide hazard zonation - a review of principles and practice, UNESCO, Paris, 1984.
2. 2) ISO/IEC GUIDE 51 : Safety aspects - Guidelines for their inclusion in standards, 1999.
3. 3) ISO/IEC GUIDE73 : Risk management - Vocabulary - Guidelines for use in standards, 2002.
4. 4) ISO12100-1 : Safety of machinery - Basic concepts, general principles for design - Part 1: Basic terminology, methodology, 2003.
5. 5) ISO12100-2 : Safety of machinery - Basic concepts, general principles for design - Part 2: Technical principles, 2003.