Yellow Trolleybus and Blue Buses can take you anywhere in the city and in the suburbs (as its mentioned in Athens trolleybus map). The Trolleybus run on electricity and the stops are usually yellow. The Blue bus-stops are blue. Tickets must be bought from a kiosk or at special stands in main squares and at some bus terminals. They are sold individually or in bundles of 10 and must be validated by a machine on the bus. They can be used for 90 minutes so in other words if you want to connect with another bus or even the metro or the tram you have 90 minutes where the transportation is covered in the price of that ticket. Electronic ticketing soon will also become available.