References in the text should be ci

References in the text should be cited as author-year when there is only one author; use “and” when there are two authors. With three or more authors, use “et al.” after the first author. Two or more references included as a group in the text are listed in chronological order. Several references in the same year are listed alphabetically. For two or more articles using the same within-text citation, add a distinguishing letter to the year (a, b, c, d, etc.) in both the text and the References section.