For decades, Pieter was friend with Czechian Mushroom Scientist Miroslav Stanĕk.
Mind you, this was still during the era of Communism!
Dr. Stanĕk participated at several ISMS Congresses, like in 1969 in Hamburg where he lectured about 'The effect of cellulose-decomposing microorganisms on the growth of the mushroom'.
ISMS London in 1972 where Dr. Stanĕk lectured about 'Microorganisms Inhabiting Mushroom Compost during Fermentation'.
ISMS Tokyo and Taipei 1974 'Bacteria Associated with Mushroom'. Pieter missed that one, due to his kidney stone problem he ended up in the hospital and one of his teachers presented his lecture instead.
ISMS Bordeaux in 1979 was another where Dr. Stanĕk lectured.
Dr. Stanĕk's wife also was a microbiologist but, during Communism it was never allowed for husband AND wife to travel both outside of the country! Just imagine that...
Equally complicated it was for entering from the FREE WEST into any communist nation!
They could be very nasty behind the Iron Curtain.
When Pieter produced an invitation for lecturing, with his name and photo, he suddenly became a most welcome 'Comradsky'...
Here, Pieter is seen in the 1970s in Prague at one of their Conferences, Dr. Stanĕk is seen on the right.