I don't get this. The question asked for a reference to something explaining the point to the Hilbert transform. I provided a link to an excellent article explaining the point to the Hilbert transform. Got deleted. The only explanation was a comment saying that it would be better to provide the essential points in case the link becomes invalid.
What does reference-request mean, if not a request for a reference? The link was to Wikipedia.
Is it better for that question to have no answers, as now, or a somewhat lame answer? (Yes, the answer was a lame anyone-could-find-that-on-google sort of thing. But that applies to the question. When the question is a "can you spell google?" sort of question why is an answer like the one I gave wrong?)