1. Collum intertextumn-a case report of a campanological crisis;Guly, H.R.; Roberts, S.B.;Injury,1982
2. Brown MBMMcC. Coping with crises in campanology;Injury,1978
3. Need for a medical advisor? Ringtng World 1989; No 4093: 8%. 4 Lee KG. Table a hazard. Ringing World 1984; No 3815: 489. S Lucas PB. Safety in the tower. Ringing World. 1988; No 4039;Richards, R.
4. The history and art of change ringing;Morris, E.,1931