This is a slightly modified version of the original dcu.bst style, which features the following changes (last updated: 2012-08-29, if there are any newer commits, I might have forgotten to update this list):
- URL access date is displayed right after the URL (from the "urldate" field), with the following format:
- URL: (last accessed: )
On Mac OS X, you can clone this repository into the
~/Library/texmf/bibtex/bst/
directory (which you might need to create). You should then by able to use the style like any built-in one.