example of custom search on nature, pubmed, ieee etc: <a href="https://www.reddit.com/r/scihub/comments/on3ddj/is_there_a_scihub_of_databases/h5papak/?utm_source=reddit&utm_medium=web2x&context=3" rel="nofollow">https://www.reddit.com/r/scihub/comments/on3ddj/is_there_a_s...</a>