1. Towers: A Historical Survey;Heinle,1989
2. Leaning towers;Heyman;Meccanica,1992
3. The conservation and structural restoration of architectural heritage;Croci,1998
4. Post collapse analyses of a medieval masonry tower;Calvi,1990
5. The collapse of the civic tower of Pavia: a survey of the materials and structure;Binda;Mason. Int.,1992