The most reliable way to get a digital version (which functions like a PDF) is through the official La Settimana Enigmistica The App "A- some" : The publisher offers an official app (available on "La Settimana Enigmistica - Scrivi" Interactive Solving
Do not download or share copyrighted issues without permission. Use official sources, subscriptions, public-domain back issues, or licensed retailers. La Settimana Enigmistica Pdf