Yes, The Sacred Marriage. I really don't know of any good articles on this topic. I'm sure you know that it's a ritual that's performed in some Witchcraft rites and Wiccan rites either symbolically or between two people who are representing the Goddess and God. However, I've not seen much written about it on the internet.
Have you tried Googling it? I'll have a look around for you, there must be something out there.