Here's the truth: you probably WON'T ever see anything published directly about them.
Why? Couple reasons.
1) Herbal abortions can be dangerous and poisonous. By design, the formulations are toxic.
2) No midwife worth her salt would simply hand out that information to a person she was not directly involved with and could supervise. There is basically an unspoken rule among those of us who know formulations never to publish them.
There do exist herbal abortifaecents (which are nothing close to reliable in terms of effectiveness or safety), as a combination of herbs. But no one should EVER use them alone, or without a naturopaths or midwives supervision, and in terms of herbalist ethics, abortions are one of those things that none would advise unless an early-term medical abortion was completely impossible (read: illegal).
Editor and Founder, Scarleteen
"If you're a bird, be an early early bird --
But if you're a worm, sleep late." - Shel Silverstein