Adding "Retrieved from URL address" when DOI is absent in model5-names.bst (elsarticle.cls)

Question

I would like to add "Retrieved from URL address" when DOI is missing for online articles in the bibliography of model5-names.bst (elsarticle.cls). This is in accordance with the APA 6th style.

For example:

Kanizsa, G. (1976). Subjective contours. Scientific American, 234(4), 48–52. Retrieved from http://www.address.edu (when doi is missing)

rather than:

Kanizsa, G. (1976). Subjective contours. Scientific American, 234(4), 48–52.

Thank you.

Answer 1

To get the desired output, you need to change the \URLprefix macro (to change the prefix before the URL string), the print.url function (to suppress printing if a non-empty doi string is present), and the fin.entry function (to suppress the . at end of the formatted entry.

• Change the instruction (ca. line 1686)

  "\providecommand{\URLprefix}{URL: }"
  

  to

  "\providecommand{\URLprefix}{Retrieved from }"
  

• Change the print.url function (starts ca. line 995) from

  FUNCTION {print.url}
   {url duplicate$ empty$
     { pop$ "" }
     { new.sentence
       urlprefix "\url{" * swap$  * "}" *
     }
     if$
   }
  

  to

  FUNCTION {print.url}
   {url duplicate$ empty$
     { pop$ "" }
     { doi empty$
       { new.sentence
         urlprefix "\url{" * swap$  * "}" * }
       { pop$ "" }
       if$
     }
     if$
   }
  

  The new code chunk checks if the doi field is empty; only if that's the case, the formatted contents of the url field are printed.

• Change the fin.entry function so that it looks like this (this will suppress printing a . if either a doi or a url field is non-empty, incorporating your earlier query):

  FUNCTION {fin.entry}
  { doi empty$
      { url empty$
        { add.period$ }
        { }
        if$ 
      }
      { }
    if$
    write$
    newline$
  }
  

---

Addendum: Here's an MWE (minimum working example) that has two bib entries: one with both url and doi fields, and one with only a url field. If both fields are present, only the doi is printed; if only a url field is present, it's printed out, prefixed by "Retrieved from URL address ". (A separate comment: the modified bst file incorporates your earlier two requests as well: (i) showing the number field, in parentheses, and (ii) no period at end of entry if doi field is printed.)

\RequirePackage{filecontents}
\begin{filecontents}{mybib.bib}
@article{abc,
   author  = "Anne Author",
   title   = "An entry with both doi and url fields",
   journal = "Thoughts",
   year    = 3001,
   volume  = 1,
   number  = 2,
   pages   = "3-4",
   url     = "http://xyz.com",
   doi     = 12345678,
}

@article{def,
   author  = "Annie Author",
   title   = "An entry with only a url field",
   journal = "Thoughts",
   year    = 3002,
   volume  = 5,
   number  = 6,
   pages   = "7-8",
   url     = "http://xyz.com",
}
\end{filecontents}

\documentclass{article}
\bibliographystyle{mymodel5}
\usepackage{url,natbib}
\begin{document}
\nocite{*}
\bibliography{mybib}
\end{document}