For "articles", nearly none; I save a copy of about 80% of articles I actually read and save essentially none for reading later. Of some high end, long PDF fi

For "articles", nearly none; I save a copy of about 80% of articles I actually read and save essentially none for reading later. Of some high end, long PDF files, say, of books, I glance at good descriptions and save a copy if the content looks good. For the famous CLRS, I read through it quickly, saw a lot of poorly done material, but did keep a copy. For such PDF files, my intention is to have them for reference later if needed; otherwise rarely do I have any intention of actually reading them. For high quality books I haven't read but would like to, I have a big but old stack. But mostly those books were to help my career, and my career has taken another path. For that path, I have essentially nothing collected but yet to read.