1. Finnish Tunnelling Association MTR-FTA, 1997. The Fourth Wave of Rock Construction. Environmentally Responsible Underground Design, Engineering and Application, WSOY, Porvoo, Finland (ISBN 951-96180-2-3).
2. Helsinki City, 2009. The Helsinki Underground Master Plan, Brochure, Helsinki City Planning Department. .
3. Helsinki City Council, 2010. Helsingin maanalaisen yleiskaavan hyväksyminen’ (Approval of the Underground Master Plan), Decision number 16 (Khs 2009–237), 8 December 2010, Decision-making history from the Appendices. (in Finnish).
4. Helsinki City, 2013. Building Helsinki, Leaflet of the Helsinki City Real Estate Department. .
5. Kivilaakso, E., 2013. Kasvava ja kehittyvä pääkaupunki tarvitsee maanalaisia tiloja. (Growing and Developing the Capital Needs of Underground Spaces) The Day of Underground Possibilities, MTR-FTA, 11 April 2013, Helsinki, Finland (in Finnish).