I do not see the “Reference comment” button in the Kudoz. Why?
Once you posted a Kudoz answer, you will not be able to post a reference. It is assumed that you put all the information in your Kudoz answer. This makes your answer a more useful resource, and ensures all the information is kept in one place. It is possible to post a reference and then an answer, but not possible to post an answer first and then a reference.