4Lunardi P, Cassani G. Construction of an underpass at the Ravone railway yard in the city of Bologna.- aspects of the design and construction [C] // Progress In Tunneling After 2000, Teuscher, P. and A. Colombo (eds.), Bologna, 2001, 3:319.
5Feng Weixing. The construction method of starting tunneling in special geological condition[C]//Yuan Jianxin. Computer Methods and Advances in Geomechanic. Rotterdam: A. A. Balkema, 1997:1413.
