I found the same thing - a real dearth of info out there. In fact, in order to tackle this, I've started my own blog along these lines. Do feel free to have a look if you want: www.mamanotmummy.blogspot.co.uk
I'm certainly no expert, but thought it would be good to get something out there.
Mmm, I have been looking for over a year and can't find anything that I can relate to. I found the above book tended to stereotype and the women speaking saw themselves as "lesbian fathers" who took on a slightly distant bread winning role rather than seeing themselves as two mum's parenting together.
I haven't even been able to find a blog or twitter discussion, so if anyone else knows of any I'd love to hear about them.