Dickins D. W. (2001). Equivalence is to do with symbols, and it is cognitive, European Journal of Behavior Analysis, 2(1), 53-56. doi:10.1080/15021149.2001.11434171
[Citing Place (1995/6)]  
Citing Place (1995/6) in context (citations start with an asterisk *):
* Tonneau disputes (p.2) that the relation between a symbol and its referent is one of symmetry in the stimulus equivalence (SE) sense. He cites difficulties that Vaughan (1989) had, and these resemble similar problems that occurred initially to Ullin Place, which he later felt he had resolved (Place, 1995. See also Dickins & Dickins, 2001). The crucial relation is between the symbol and the signs of the referent, not the referent “itself ”. Thus the referent of the symbol “dog” constitutes a host of aspects of encounters with dogs - sounds, sights, smells .. - the whole experiential structure in fact which constitutes the meaning of that word. Additionally the symbol itself (the word “dog”) exists in many forms - spoken, heard, written, read - to which may be added corresponding words in other languages, all freely interchangeable, just like the constituents of a (welltested) equivalence class.