PA2HJS (now PA2S) and co-editor PAoERA (now PF5X) wrote this study about 50 MHz propagation in The Netherlands.
When the 50 MHz permits were issued in The Netherlands in 1988, it was agreed with the authorities that we should report about the results of the experiments on 50 MHz.
The aim of the study was to correlate 6 meter openings to environmental properties, like solar flux, magnetic activity and the like.
The document was created with MacWrite on an Apple Mac computer. Using an emulator (Basilisk with Mac OS 7), the document was printed to a Postscript File and converted to PDF.
The layout is not perfect, but…
Here is the document -> 50 MHz Study (PDF)