Regensburg is well connected by public means of transportation.
For train tickets you can look at:?
www.bahn.de
The closest German airports are:
München (Munich) - distance 132 km, 1.5 hours by car,
Nürnberg (Nuremberg) - distance 124 km, 1.5 hours by car,
Frankfurt (Francfort on the Main) - distance 345 km, 3.5 hours by car.
There is an airportliner commuting between Regensburg and Munich or Nuremberg airport, Reservation can be made at:
www.airportliner.com
Further information is available on the University