I don't have a direct reference but I read that Dirac once remarked, “a photon can only interfere with itself”. But I recently came across a website in which it is written
The manifestations of wave-like behavior are statistical in nature and always emerge from the collective outcome of many electron events. In the present experiment nothing wave-like is discernible in the arrival of single electrons at the observation plane.
Is there a contradiction between the view expressed by Dirac and the view expressed in the website? Or am I mistaken?