Often I'd like to cite an electronic version of a book. It will be by a scientific publisher, and have all the publisher, editor, etc. information, but has a URL and an accessed-on date instead of a page number. I've got to choose between @book which won't give the URL and pretend I went and got the hardcopy (Which seems unethical) and @online which misses half the information and makes it look like I used a website. Is there a way to add the accessed on date and URL to a full book entry? Or some form of hybrid style?
Example books: IUPAC gold book. CRC Handbook of Chemistry And Physics.