You can visit any DB (Germany) or SBB (Switzerland) ticket counter and they should be able to sell them for you. If it doesn't work, ask them to try with the train number
Availability shouldn't be a problem if you buy them when you arrive in Spain. There are trains every 30 minutes between the 2 cities
You can visit any DB (Germany) or SBB (Switzerland) ticket counter and they should be able to sell them for you. If it doesn't work, ask them to try with the train number
Availability shouldn't be a problem if you buy them when you arrive in Spain. There are trains every 30 minutes between the 2 cities