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(en) (fr) (de) LRT - A Dynamic Transit Mode With Continuing InnovationsThe former group of cities eliminated streetcars / tramways. The latter upgraded them through numerous innovations, into Light Rail Transit - LRT. ↔ Le premier groupe de villes a supprimé les tramways tandis que le second, grace a de nombreuses innovations, les a transforme en métros légers. geraadpleegd op 2023-10-02.
(en) Cappelli, Agostino, Nocera, Silvio, Libardo, Alessandra(2013).Environment, land use and transportation systems: selected papers,p. 42.Geraadpleegd op 22 March 2024"Rather soon attention was given to Light Rapid Transit modes such as pre-metro and semi-metro (Hannover) employing heavy trams instead of light trains to run on open-air independent or semi-independent tracks, and just and just seldom using short bypass tunnels or fly-evers to skip congestion in central areas."
Transportation Research Board National Research Council(1989).Urban Public Transportation Glossary.Geraadpleegd op 16 February 2023"pre-metro: a light rail transit system designed with provisions for easy conversion to rail rapid transit"