from Danish Ministry of Transportation media release: https://www.trm.dk/nyheder/2022/undersoegelse-af-2-km-lang-tunnel-i-aarhus-saettes-i-gang/

Deutschebahn New Railway Tunnel between Hamburg CS - Altona Deutschebahn press release

Webuild Brenner Base Tunnel projects - graphic by Webuild p. release

Jeju Tunnel Korea

Moscow Big Circle Line - Moscow Mayor Official Site under a Creative Commons Attribution 4.0 license. from:https://www.mos.ru/en/news/item/101314073/

NTB Norway Nye Veier 7 tenders in 2022  - NTB press release on 19 January 2022.

Singapore Land Transport Authority CCL6 T Cantonment and Keppel Stations (LTA press release)

Singapore Land Transport Authority CCL6 Tanjong Pagar Station (LTA press release)

Singapore Land Transport Authority CCL6 Map (LTA press release)

LTA CRL1 Aviation Park Station and Changi East Depot plans -  Singapore LTA press release