Note: The booklets state that they were published monthly - but this can also be interpreted as one every four weeks. Fan Magazine "Blick in die Zukunft" #19/20 for Sep/Oct 1958 lists the first 3 books for August 1958 - and repeats the same three books for September 1958. Five books were published in total, all from the Gebrüder Zimmermann Backlist.