I assume that it has about the same content as the book "Informal introduction to algol 68", published by the same authors a few years later, and which had at l

I assume that it has about the same content as the book "Informal introduction to algol 68", published by the same authors a few years later, and which had at least two editions, e.g. in 1973 and in 1977. Searching the Internet finds some scanned copies of that book. E.g. https://www.softwarepreservation.org/projects/ALGOL/book/Lindsey_van_der_Meulen-IItA68-Revised.pdf https://www.softwarepreservation.org/projects/ALGOL/book/Lin...