Analysis of information sources in references of the Wikipedia article "Dennis Dart" in English language version.
Citybus became a pioneer of gas bus operation, in an EU-funded joint project with local councils. Branded as Ecobus, it launched in 1994 with the conversion of six existing Dennis Darts in the fleet. Joined by 10 new ones delivered in 1996, it made Citybus the largest operator of gas buses at that time. They lasted for around 10 years.