BKK

https://web.archive.org/web/20190510104012/https://alfahir.hu/2019/05/08/gyongyosi_mate_kozlekedo_tomeg_egyesulet_budapest_bkk_tomegkozlekedes_bkv_tarlos_istvan

E-Ticketing

Source – National AV Archives

Source – National AV Archives

BKV

Air Conditioning

24.hu video

Source

Video with Balázs Kaufmann

Source