Antonyms for the phrase "made reference" could include "omitted," "ignored," or "neglected." These terms suggest that there was a deliberate decision not to mention something, rather than actively making a reference to it. Other antonyms could be "dismissed," "disregarded," or "overlooked," all of which signify a lack of value or importance placed on the subject. Conversely, synonyms for "made reference" would include "referred to," "alluded to," or "cited," all of which signify actively bringing attention to a topic. The choice to use one of these antonyms over another can affect the meaning and tone of a piece of writing.