Heinz Werner, »Intermodale Qualitäten (Synästhesien)«, in: Handbuch der Psychologie, Bd. 1:Allgemeine Psychologie: I. Der Aufbau des Erkennens., (ed.) Wolfgang Metzger (Göttingen: Verlag für Psychologie, 1965)

»When we say that a tone is strong or weak, that a pressure is strong or weak, we are no doubt referring in all cases to a property that is the same in all these sensory domains. Recent research has now shown that there are doubtless many more properties than psychology previously assumed that, like intensity, can be called intersensory.«

@incollection{Werner.1965,
 author = {Werner, Heinz},
 title = {Intermodale Qualit\"{a}ten (Syn\"{a}sthesien)},
 volume = {1, 1. Halbbd.},
 publisher = {Verlag f\"{u}r Psychologie},
 series = {Handbuch der Psychologie},
 editor = {Metzger, Wolfgang},
 booktitle = {Handbuch der Psychologie, Bd. 1:Allgemeine Psychologie: I. Der Aufbau des Erkennens.},
 year = {1965},
 address = {G\"{o}ttingen}
}