The CTS used to refer to specific passages in Athenaeus has the possibility to “subreference”, i. e. to refer to a smaller portion of a chapter, e. g. a sentence, or even just a word.
Philologist, on the other hand, can easily produce such references.
The address of a specific word in Ath. 15.56 then looks like this:
http://data.perseus.org/citations/urn:cts:greekLit:tlg0008.tlg001.perseus-grc1:15.56#Ἀγαθοκλεῖος1
And here is the address of a longer passage:
http://data.perseus.org/citations/urn:cts:greekLit:tlg0008.tlg001.perseus-grc1:15.56#Ἀγαθοκλεῖος1-ἤλασαν1
To produce such references, call up an Athenaeus chapter, and then simply select a word, or a passage, using the mouse. It will change color, and the address in the “Uri for target” window will change (check it out).