The pamphlet has no publishing date printed on it. The pamphlet is however advertised in Dutch newspapers “Utrechts Nieuwsblad” of March 2, 1966 and “Noordhollands Dagblad” of February 25, 1966. The publishing date of February 1966 is therefore an educated guess, and the actual publishing date may be earlier than that.
Pamphlet published in February 1966