In today’s Toolblog, the Luhmann-inspired method of zettelkasten is discussed. To understand it, read https://x28newblog.wordpress.com/2016/12/01/magic-of-zettelkasten/
Update 2017-09-07: continued here http://toolblog.de/2017/09/04/in-eigener-sache-wer-kennt-sich-mit-luhmanns-zettelkasten-aus/