That's a fair point. Generally I am used to seeing a cite of original source on an elaboration, proof, or "let's dig into how it works" sort of writeups on algo

That's a fair point. Generally I am used to seeing a cite of original source on an elaboration, proof, or "let's dig into how it works" sort of writeups on algorithmic approaches. (Sometimes this is done even when the algorithm in question and source is well known.) Specially if the author is an academic.