Here, I only intend to highlight some outcomes concerning the difficulty of using clear references even for English expert authors. On average, the RAs in my corpus contained six vague items or ambiguities each. The most frequent referring items with vague referents were the results and the data. Many times, the antecedent (referent) was not clear when groups of participants were referred to: sometimes it was unclear which group or subgroup was being described. (Once the original published layout had to be checked: for the identification of the referent of these passages.) Vague references included items as: in the ways described above, in the initial stages. Once, the referent of an abbreviation with a definite article was missing. These ambiguous and vague references support the position that the usage of referring items in a way that all references are clear and the text is easy to follow is not only difficult for non-native writers, but for expert writers as well.