"Fortunately, the trademark laws are fairly cut and dried. To be in violation, you either need to be using a trademark without permission in a way likely to cause confusion, or using the trademark in a way that causes "trademark dilution" which "dilutes the distinctive quality of the trademark". You seem to be doing neither in this case."
Note - I am not a lawyer, I just found and paraphrased this by googling "referencing a trademark"