It is the only trolleybus system ever to have been constructed in that country.

That left the trolleybus system as the town's only form of public transport.

For a brief period in the 1930s, it even had the distinction of being the world's largest trolleybus system.

All other trolleybus systems in China opened after 1950.

It was the only trolleybus system ever to be built in Ireland.

Nine cities in this former Soviet republic have had trolleybus systems.

Earlier, at least 12 trolleybus systems existed in Spain; see list.

It was the only trolleybus system ever to be constructed in that country.

The first trolleybus system was established in 1946 and lasted until 1973.

It is the only trolleybus system ever to have existed in Iran.