Not everything I claim to know/be true is basic (say, Horowitz/Hill or part's data sheet) or self-invented.
I am aware of the help on How to reference material written by others.
What is the politics (forbidden/deprecated/tolerated/recommended) where the reference material isn't in English?
There is a range from translation true to the best of one's capabilities to interpretation, in English for this site.
When presenting something as a (block-) quote, striving for the former seems prudent, and identifying originator and source natural.
I don't find it as clear where "just" trying to present an idea with a focus on understandability, but aware of one prominent inspiration.
Triggering this meta-question was a late addition triggered by a comment to my answer about an LED driver design, I felt it was off not to mention Eberhard Haug, slept over it, added hyperlink&co - and don't like it any better.
(The answer may be more useful now - rev. 2 was succinct.)