Thanks! I've followed references and I think I have the original paper: http://pages.stern.nyu.edu/~aalter/intuitive.pdf

We recruited 40 Princeton University undergraduate volunteers at the student campus center to complete the three-item CRT (Frederick, 2005). Participants were seated either alone or in small groups, and the experimenter ensured that they completed the questionnaire individually. Those in the fluent condition completed a version of the CRT written in easy-to-read black Myriad Web 12-point font, whereas participants in the disfluent condition completed a version of the CRT printed in difficult-to-read 10% gray italicized Myriad Web 10-point font. Participants were randomly assigned to complete either the fluent or the disfluent version of the CRT (...) As predicted, participants answered more items on the CRT correctly in the disfluent font condition ... Whereas 90% of participants in the fluent condition answered at least one question incorrectly, only 35% did so in the disfluent condition.