AMS Citation Style - No date When including a reference in your bibliography, and the source has no publication date, how should this be indicated in the AMS (American Mathematical Society) citation style? Is it &quot;n.d.&quot; or should the date simply be omitted?
I would say, yes, n.d. is correct.
Background: The AMS Style Guide is based on the Chicago Manual of Style (see the Preface at p. ix), so let's take a look there (at chapter 17.119):

When the publication date of a printed work cannot be
ascertained, the abbreviation n.d. takes the place of the
year in the publication details. A guessed-at date may
either be substituted (in brackets) or added. [...]

For the &quot;guessed-at date&quot;, the Chicago manual provides the example of (Author [1750?]).