After messing around on the net to find some good links, I decided to drop it there and ask the BibDesk community. Interestingly, it was an open topic but fortunately James gave me the right link. He realised a url’ized version of the apalike.bst. I attach it here for your references (I hope is okay James). I also add some instructions on how to hack the file in the extended part (contributions of James and Claus, from the mailing list).

[apalike-url.bst]

To use the file (James):
————————
You need to set up two things. The first is to adjust the bst file to
output URLs properly. I do this with urlbst which you can download
from CTAN. To save time I’ve attached a url’ized copy of apalike,bst
for you …

Then you fill out the url field in Bibdesk

To get the “Accessed on” part of the entry you need to add a field
using the plus sign in Bibdesk and name that field lastchecked (make
sure to use lower case, but that’s a bug we’ve fixed for the next
release …) and drop it in there.

You should be able to put the apalike-url.bst in either your texmf tree
or in the current directory … I keep mine in ~/Library/texmf/bibtex

To hack the file (Claus):
————————-

Let me summarize what I did with apalike to incorporate the new field =20=

eprint. This should work with any style file. Some text is made bold to =20=

emphasize modifications.

Claus

1) Add eprint to

ENTRY
{ address
author
booktitle
chapter
edition
editor
eprint
howpublished
institution
journal
key
% month not used in apalike
note
number
organization
pages
publisher
school
series
title
type
volume
year
}

2) Add a function how eprint should be formated. The mbox construction =20=

is certainly special because of the url’s. Check where this occurs in =20=

apalike modification and add it at a similar place.

% Function modified to wrap the eprint number in an mbox construction – =20=

GJK

FUNCTION {format.eprint}
{ eprint empty$
{ “” }
{ “\mbox{” eprint * “}” * }
if$
}

3) The next modification is very important

Do a find/replace all (e.g., in BBEdit)
Find: note output

Replace: format.eprint output\r note output

such that the result is

format.eprint output
note output

This insures that the field eprint appears before the field note.

4) Find at the end the file

FUNCTION {begin.bib}
{ preamble$ empty$ % no \etalchar in =
apalike
‘skip$
{ preamble$ write$ newline$ }
if$

or any similar form, and add

“\providecommand{\bysame}{\leavevmode\hbox =20
to3em{\hrulefill}\thinspace}”
write$ newline$
“\providecommand{\href}[2]{#2}”
write$ newline$

such that the result looks like

FUNCTION {begin.bib}
{ preamble$ empty$ % no \etalchar in =
apalike
‘skip$
{ preamble$ write$ newline$ }
if$
“\providecommand{\bysame}{\leavevmode\hbox =20
to3em{\hrulefill}\thinspace}”
write$ newline$
“\providecommand{\href}[2]{#2}”
write$ newline$
“\begin{thebibliography}{}” write$ newline$ % no labels in =
apalike
}

This is the place to add additional tex commands to the preamble of the =20=

bibliography.

————————
UPDATE (20th of May 2008): While working on my thesis, I found a better way to produce apa-like citations with a seamless URL support. The package is called APACITE, a package developed by Erik Meijer. In order to have a perfectly spaced URLs you also need to use the URL package, which comes standard with almost every LaTeX distribution.