00322nam a2200109Ia 4500008004100000082001200041082000800053245008800061245002700149260002700176300000900203231017s9999    xx            000 0 und d  a551.307  bRUS 0aModification and Statistical Analysis of the Colorado Rockfall Hazard Rating System 0cChristopher P. Russell  bChristopher P. Russell  c30cm