If I want to quote a reference in an answer on this site, I use the syntax
[Here] followed at the end of the answer by
Here is an example.
But this doesn't work in the comments. What should I do instead ?
You should use the following format:
I will add that this information is shown when you click on "help" while writing a comment. (See the picture below. Similar picture can be found here.)
If you then click on "learn more", you will get to the section of the MarkDown help concerning comments: http://math.stackexchange.com/editing-help#comment-formatting