PubMed is the National Library of Medicine's search service that provides access to over 10 million medical and scientific citations. I encourage you to use this service for your research. After you review the abstract you can order the entire article online, or you may go to your local medical library.
Every medical school is associated with a medical library.
I have been told that estriol is a better choice than estradiol because it does not stimulate cells the same way that estradiol does. Is estriol really safer, or does it have the same risks as other estrogens. And may actually contain more risks. To fully understand this we have to first review estrogens, then review estriol and its metabolite 16-hydroxyestrone. We do know that estriol has estrogenic properties though considered to be weaker than estradiol.