Dear Saverio,
I will take advantage of your post to provide information also to all the others who may benefit from it.
While asking TheSimon (or anyone else on any other site) to convert articles into PDF would oblige him to:
1. Buy software to produce the format (software that is not cheap at all)
2. Use his own work to convert existing content and update the site with new content (even the labor is not cheap),
there are, instead, other solutions that each of us can practice without burdening others, not only, but even gaining other advantages.
One is the use of various format converters, but they are generally paid and age rapidly if they convert proprietary formats (because the producer of the starting format innovates and the publishers using that format use its new features); therefore you must update continuously and pay continuously.
If you do not like this "consumerist" approach, there is instead, at the expense of each of us, a possibility that I have already, if I am not mistaken, recommended once more, but "REPETITA JUVANT"; it enables you to have in PDF everything you need and not just the stuff from this site.
In essence, it consists of activating a "virtual printer" on the computer, i.e., a driver (which is a program) that pretends to be a printer and instead produces a file in PDF format.
In this way, provided that the site allows printing or downloading (in this second case you need software to read the format and print it), you have all the PDFs you want; the obvious downside is that you may lose some functionality (if the site does not allow downloading), as certain editorial structures can be lost (For example: if you print an electronic score, the resulting PDF file contains the graphic image and the information on notes, embellishments, dynamics, etc., is lost, even if the textual part is preserved [if the application used/the driver is intelligent!]). One consequence is that the resulting PDF file generally "inflates," meaning it takes up more space, but memory now costs very little.
I, for example, on Windows use Bullzip PDF Printer (free), while on Ubuntu I have activated Cups-pdf (Open source).
For Mac we hear that TheSimon recommends TheSimon.
Hello and Happy New Year