RCCAO - Major Cost Drivers in Tunnel Projects - Toronto, Canada.
From the RCCAO report titled: Station to Station. Why Subway Builing Costs Have Soared in the Toronta Region'
CPK Long Distance High Speed Tunnel in Łódź, Poland
origin:CPK Media article The construction of the CPK long-distance HSR tunnel in Łódź has begun. The construction contract has now been signed – Centralny Port Komunikacyjny – CPK