Stray comma after title of anonymous book

EndNote EndNote Styles, Filters, and Connections
1

I am consistently getting a comma after the title of a book with no author, i.e., an anonymous book.  Can someone suggest a way to fix this?

The citation ends up looking like this:  

Gun Control Laws in Foreign Countries,  (Washington, D. C.: Library of Congress, Law Library, 1981)

and

Guide to the Manuscript Collections of Friends Historical Library of Swarthmore College,  (Swarthmore, Pa., 1982)

3

The style is “J Amer Hist.ens”

4

I forgot to say that I just want to get rid of the comma.