# The opening conditions of the metro and its early characteristics: A historical perspective

> Research article (Tunnelling and Underground Space Technology, 2020) · cited 10× · AI/ML

**Wikidata**: [openalex:W3111756814](https://www.wikidata.org/wiki/openalex:W3111756814)  
**Source**: https://4ort.xyz/entity/the-opening-conditions-of-the-metro-and-its-early-characteristics-a-historical-perspective