Publications about Railways in the Balkans and Turkey
Since 1968, Dr. Hans-Peter Bärtschi has made a dozen trips to Turkey, Bulgaria, Albania and Yugoslavia. Back in the socialist era, he was arrested more than once for shooting photos of industrial and railway sites. At present, the trips are subject for the publication "The East was Red – Journeys to the Heart".
Further information and references:
Industriekultur Schweiz - Europa – Global (German)
p. 78 – 81