I keep some ebooks/PDFs or long form articles open for this purpose. Preferably something lightly technical that I can read a few paras at a time and highlight

I keep some ebooks/PDFs or long form articles open for this purpose. Preferably something lightly technical that I can read a few paras at a time and highlight as I go along. Ideally the piece should be self contained and not link out to other places, and something that has stood the test of time, so that I stay invested in finished it. I've skimmed and re-read a few books this way. And even the occasional paper.