After I wrote an article for the NVBS (a Dutch train hobby club) I got some nice replies. One person, Kees van de Meene, was so kind to share a short video he made in May 1977 when he traveled the Belgrade- Bar railway which was part of Yugoslavia back than.
The railway opened in May 1976 and the electrification was not yet finished. At the end of 1977 the electrification was completed, so in this video you can see a famous diesel locomotive from the USA, the EMD G16. Th Yugoslav Railways numbered them ” JŽ series 661 ” and they even had a nickname: “Kennedy”.
With kind permission of Kees van de Meene I could share this video, which you can see below.