Citation, Documentation of Sources

Q. I’m applying the author-date system in my Ph.D. dissertation. When I have several references to the same source within the same paragraph, I have been attaching the date only for the first citation. For example: “. . . was introduced by Nasberg (1985). . . . The basic formulation in Nasberg’s model is . . .” Is this policy okay? A pre-examiner of my work disagrees on this.

A. Although Chicago style would allow the method you are using (please see CMOS 15.25), perhaps your university doesn’t. You should check with the dissertation secretary of your institution.